The biggest problem for a stealthed boarding craft is always going to be that you need a 10x speed edge in your boarding craft to have a successful boarding, and you are better off with a greater speed edge to avoid massive casualties in your boarders.

And while you might be able to get that speed edge vs slow commercial ship, normally you have to cripple an enemy in order to board.  Which means you need some fleet component designed to disable the enemy prior to boarding, or approaching with your boarders.

It is why my design philosophy for fast beam capital ships includes a cryo boarding module.  I don't need to worry about them being destroyed on approach, because they have already approached.

Actually, this all suddenly makes me wonder.
How long is the delay for the boarding action when breaking through a jump point?
I know fire control, active sensors, and the like are jammed, as well as a slight orders delay, but if it's much shorter than using weapons you could probably do some spicy jump assaults that heavily rely on boarding hostile vessels in range of the jump point.
Not pertinent to stealth ships though, obviously, except for the fact that it'd be sneaky in of itself.

Because boarding only works at all if you have an enormous speed advantage, it is really only useful against commercial ships, disabled ships, and space stations.

For the first two, you still want enormous speed, because getting a ship all the way to zero speed risks destroying it.  If you have mostly crippled an enemy ship, it will likely be separated from their fleet, and therefore have less point blank fire power.  If you want to be safe, you can send a sacrificial 80 ton scout to check, but otherwise you are going to have to enter their envelope.  A tactic is to bait out their firepower at the edge of their range envelope, and close before their weapons can recycle, but that isn't going to protect against point defense shredding your boarding ship.

A lot depends on what you know about the enemy ships.  If they are dedicated missile combatants, you can just wait until they are out of missiles, or if they are on a 10 minute reload cycle.  If they are a beam combatant or mixed with integral point defense, you will have to risk losing boarding pods.  So the question is what are the effective and efficient ways to boarding, losing the least boarding pods?  Numbers?  Armor?  Speed? ECM?  ECM, unless you have a significant tech lead with it, is an expensive way for a fighter or FAC to defend against a capital ship.  ECM and numbers might work, if the target has a limited number of ECCM to apply to whatever is swatting the boarding pods.

Speed is going to help a bit more against missiles than point defense.  But being able to soak AMMs is going to increase the number of missiles required to disable more than pure speed is likely to.  A solo disabled ship isn't likely to have the missile density to penetrate the point defense that railgun fighters escorting the boarding pods can bring to bear.  Unless you are talking pvp, where the player will hold fire until point blank to bypass PD.

On a pure cost basis, I would generally prefer a speed + armor solution.  And it would also depend on whether I was more limited in shipyard capacity or marine companies.

Another solution is to have the boarding modules on your fast beam combatants, in cryo modules.  They are already fast, already close, and already have the armor and/or shields to be survivable, especially vs a disabled ship.  Having non-cryo boarding pods on fighters or FACS is great where you want absolute speed, for going after intact commercial ships, where you couldn't afford that engine ratio on a beam combatant.

Boarding a space station, the calculus is slightly different.  You can cross a point defense envelope before the enemy fires, and then all you lose is the boarding pod.  So cheap boarding pods would be the efficient method there, and possible have a ship at the edge of its main beam envelope drawing fire as the pods approach.

I don't see stealth boarding pods working by themselves, so evaluating them depends a lot on your doctrine of who they are working WITH.  And on whether you are talking about fighting the AI, or fighting in duels.  Or whether you want anti-player designs for RP purposes.

ECM helps most (in my opinion) in combats where both sides are using similar ranged weapons.  It can help you get off the first shot in a missile duel, or more effective in a beam engagement.  However, unless you can close the entire enemy envelope before it runs out of missiles or before it can reload, ECM isn't going to help beam ships much vs missiles, or a boarding pod versus beams.

My mistake about beam effects of ECM.

And yet you lack armor. One laser shot go through your armor and start destroying componnt. You loose your drop cryopod and it is a mission kill. You lost your engine, and it is a mission kill too. How much shots to kill your chip ? 2 ? 3 ?
Even without ECCM, a defensive turret designed to kill ASM will have a good chance to hit you as it is designed to kill far faster missiles with a huge salvo missile number.

But the true problem is not beam defense. At 25 kkm/s, you will go through their defensive range in 2 to 4 round at most. They will only get one good shot or two, with or without ECM.
But you will be destroyed by AMM fire from 2-3 millions kilometers. Do you think your design will be able to survive 16x5-sec increment ? (and more if you are chasing them ?)
You start getting internal damage with 2 to 9 AMM.

Or do you plan to expand lots of missiles to make them use all their AMM before?
IF it is your stratgy, then the ennemys ships could be fleeing, which means a lower relative speed and more time in laser range.

You need a cryopod, speed , and armor, everything else is nearly useless IMHO.
And your stealth CV lacks armor too.

In my curent game, I'm designing ships for a boarding attempt on huge spoiler defensive stations, somewhat like in the crusade campaign.
Tons of AMM and defensive beam weapon. I'll be going with several assault carriers with huge armor and some shields and CIWS, covered by huge salvoes of missile to make the AI choose between missiles and my assault carriers. Once at the laser range limit, I will launch FAC designed for boarding, with speed and armor, hoping enough will survive. plan is 3-4 assault carrier and 20-30 boarding FAC.
I plan to use the assault carrier later, as they are costly. They'll have less hangar bay than standard CV, but they will be far more hard to kill

ECM affects the accuracy of beam weapons all the way up to near point blank. Considering beam weapons will be engaging from farther than point blank, it can have a measurable affect on being engaged by long range, long cooldown beam weapons. Considering it will have an impact on missile fire control too, it means you can get closer to the hostile ship before missiles start firing, assuming he missile fire control isn't significantly overengineered.
In either case, reducing the time it takes for your ship to move into drop pod range by 10% will have a similar affect to reducing the effective range of enemy weapons by 10%, with ECM only significantly reducing hit chance of beam weapons, so it's a good ideas to compare it to engines in these respects.

Which is why I re-designed the Dagger into the Dagger II and offloaded the stealth to the Cloak-Class Carrier. The Dagger was built under the assumption that you could fire a Combat Drop module at a target from range, so the cloak would allow it to stay outside the range of AM/AF sensors (Res 1-10) and fire the Combat Module from there. Unfortunately the good people here clarified that boarding is in fact at range 0, so the Dagger II was designed with greater speed. The ECM helps you to not get hit by reducing the range/accuracy of the enemy FCS.

Yes, eventually they will see you, but that is the point of the stealth. You don't want to get shot at on the approach, so the cloak is there to keep the enemy from seeing you until the last possible moment. However, with the speed so low, it wouldn't matter anyway, so I offloaded the cloak to the carrier, which can use it to skulk around and launch the boarding craft at the target at the closest possible range.

never pulled of boarding actions, does it work? what happens when you do it?