So I finally had a chance to catch up, and found quite a suprise "shields prevent boarding attacks".
I had a search and looked through the changes post and I can't see any mention of it in the description for boarding or shields, is it new for 1.14/2.0 or is it an old feature I've never encountered?
Also I think you should come up with a naming scheme for the different sizes of battleships, may I suggest you give them ratings, like the Napoleonic ships-of-the-line? Alternatively the Yamato class is widely refered to as a Super-Heavy Battleship so maybe that would be suitable?
Also do you have something planned to give them jump capability or are they going to be kept within the stabilized jump network forever?
Given how you started tooled up for missile combat, I'm suprised at how much time and research you're putting into beams, rather than designing specific anti-swarm missiles. If you can get a missile running at 40k km/s with 25 MR then they should hit the small swarm craft pretty regularly.
I have just launched four jump-capable battleships of 18,750 tons - the Lord Nelson class. At the moment I don't have anything larger planned for jump-capable ships.
Larger battleships will become Dreadnoughts and then Super-Dreadnoughts. Going back to my Starfire roots

Missiles seem powerful, but in a large campaign they are problematic. You need to build all the missiles to arm your ships, and often build them again when engine tech improves, which limits your missile-armed fleet to the number of launchers that ordnance production can effectively support. Missiles also require Gallicite, so when you research new engines you can run into a serious Gallicite shortage as refits and new missiles compete for limited resources. Half this campaign has been spent securing Gallicite supplies and because of that I neglected other priorities which means I am about to run out of Neutronium.
Beams have none of these problems, so you can build as many ships as you like within your ability to maintain them, plus they cost a lot less in combat because they aren't consuming valuable resources every time they fire. Missile ships without missiles are just expensive targets, so I find myself reluctant to commit to a large engagement unless I know I can quickly replace the ordnance expended with modern equivalents. At the moment, I still haven't produced enough missiles to even arm all the missile ships with the latest models. I need to expand on the current 500+ ordnance factories but the Gallicite issues meant that I couldn't use that extra capacity even if I built it.
The hybrid ships are an attempt to have the tactical firepower of missiles with the strategic flexibility of energy weapons.
In terms of the swarm, I am using the energy-armed ships to combat the small craft, so I can save the missiles for use against the battleships that outrange my energy weapons. Although I just starting retooling for the energy-only Invincible class battlecruiser. Faster than a battleship (due to boosted engines) but with less armour protection (which worked so well in real history

). That is slightly faster than the Swarm capital ships so I will be able to close the range.
On the subject of boarding vs shields, I thought that was the case, but after checking the code I might be wrong
