The industrial-age NPR addition got me thinking again about warfare among races with a large tech disparity. I'm not saying conventional races should stand any chance of defeating a trans-Newtonic, interstellar empire, but as things stand, it might be impossible for any low-tech race to fight back at all due to how ECM penalty works, with any difference of 5 or above resulting in 0 chance to hit.
Conventional races are an extreme example, but I've generated Swarm races in my game that had ECM advantage of 3 or 4 over me, which forced me to turtle back and tech up until I could engage them, despite otherwise having access to tools that could allow me to fight significantly more advanced enemies (beam fighter swarms, massed missile fire, lance ships with incredibly overbuilt engines and shields would all be effective if not for their miniscule hit chance due to the ECM penalty). If the AI wasn't so meek, passive and easily deterred from assaulting jump points, there's no way I would've won that war. On the other hand, I've encountered a fair share of NPRs who were generated on small, subpar worlds, possessed very low technology and offered marginally more resistance than a Precursor ruin (also vastly outmatched in late-game), requiring no tactical finesse to conquer and presenting no danger, resulting in rather unexciting, tedious campaigns.
Honestly it kinda bugs
(haha) me how once the tech disparity is large enough, it becomes mathematically impossible for the lesser race to fight back, so I was wondering if you're willing to consider a different approach to the ECM penalty where the hit chance reduction is not additive, but multiplicative, as follows:

I think the 0.25 option would still penalize low-ECCM races enough (and make small penalties a little more meaningful while avoiding a twofold DPS reduction with ECM Penalty 3->4) but also give the underdog a semblance of a fighting chance. All of this pertains to the Missile/Fire Control Jammers, as far as I could see Sensor Jammers operate with a 0.1 additive penalty and while this makes them rather inconsequental, they're not breaking anything either. Using a larger multplicative penalty for them could be interesting as well though.
I think all the weapons should be turreted, however have some of them with some drawbacks. I know turreted Railguns would be powerful, but maybe make them limited to only twin mounts. Or buff gauss with the amount of possible shots
I'm also mildly annoyed how only some weapons can be turreted, because it could imply than every Railgun or Particle Beam is mounted in a hardpoint (so how does a retreating ship fire its railguns backwards then?) but I understand the game-necessity for it, as 10cm Railguns are already obscenely overpowered for point defense, reaching parity with Gauss only with Gauss ROF 4-6 depending on how fast your ships go, which is a rather large tech investment. In my headcanon, I get around this by viewing non-turreted weapons as mounted in large, battleship-style turrets that are only agile enough to track targets up to the ship's own speed, while a turretted Gauss or a Laser is mounted in a snappy CIWS-style configuration that can track as fast as its gear percentage and BFC speed allow.
Not sure there could be a solution for turrets that could make all these mental gymanstics unnecessary, but I think Gauss in particular could use a buff to its PD capabilities, perhaps a
Size vs Caliber setting which would allow it to deal fractional damage in return for smaller weapon size. We already have fractional damage AMMs, having a half-size gauss dealing 0.5 damage per shot would be rather nice against an enemy with Size 10 (or below) missiles, challenging the 10cm Railgun meta. This would also enable one to make truly tiny low-accuracy, low-damage guns for use on tiny beam fighters (however with small fighters, BFC size always becomes a concern).
Additionally, the whole small Gauss thing could be tied into the planned (or at least that was something I remember discussing here) rework of Ground Support Fighters, in regards to the possible
deprecation of Ground Support Pods and the use of existing weapons by fighters for both space fights and Ground Support missions. In this case, an anti-infantry fighter weapon would be needed, and a small, rapid-firing Gauss would be a perfect fit.
In regards to anti-ship capabilities of fractional damage weapons, I think it'd be nice to give them a chance to deal damage corresponding to their weapon strength (0.25 damage = 25% chance to inflict 1 damage, or if deemed too generous, use damage^2) rather than keep them completely ineffectual. The only reason I phased out my own sub-1 strength AMMs was my desire to use them in anti-ship support roles, especially by old ships relegated to garrison duty where they would mostly encounter Raiders who possess neither shields nor missiles. A weapon incapable of penetrating a single layer of armor still being able to inflict damage to it occasionally could easily be explained by metal fatigue, weak projectiles striking the same spot enough times to overwhelm its structural integrity.
Also, while you got me yapping about weapons, I think Particle Beams (and especially Lances) not fitting into Spinal mounts is a crime. A Spinal Lance is such a widespread sci-fi trope, it honestly feels weird not having access to them. Not to mention how this would fit the Lances' implementation (tremendous penetrative damage, agonizingly long reload) absolutely perfectly.