Disclaimer: I am, of course, ignoring semantics and any lore-related shizz about the names of hullmods. Please don't argue that "the names make more sense with what they do right now don't change it", because A) that's been pointed out to me already and if a name needs to be changed I'm not going to stop it, and B) that's not what's being discussed here.
This just cropped up in a discussion on the usage of the Reinforced Bulkheads hullmod in the Unofficial Starsector Discord, and I raised (what I thought was) an interesting argument on why it's so preferred over it's not-so-sidegrade hullmod Blast Doors.
Reinforced Bulkheads, as we should all be familiar with, does two things. First, it "almost" guarantees the ship will be recoverable if destroyed in battle (and, y'know, stops it breaking into bits if it does). Then, it gives the ship +40% hull integrity. Pretty damn good all-round.
Blast Doors, from what I can tell much less commonly used, also does two things. First, it reduces the amount of crew losses taken due to hull damage in combat, and likewise when the ship is destroyed. Then, it gives the ship +20% hull integrity.
The problem I'm seeing is that Reinforced Bulkheads is quite often a no-brainer. Having a ship be "almost" guaranteed to be recoverable after a battle is great, whether you're a new player or not. Ships die a lot, and it's very nice to be a little more relaxed about ships dying. Then there's that 40% extra hull (that's a damn lot on some ships!) which is always just as welcome.
Blast Doors, in contrast, seems a less obvious choice in many situations. I'm aware it's designed for the same role as Bulkheads: in a fleet of expendable "junkers" that are regularly destroyed and recovered, Bulkheads does the recovery while Blast Doors ensures you don't run out of willing sacrifices I mean, ah, crew members in the process. However, crew losses from combat never seem very high to me. Perhaps they should be more punishing, but that's a different Suggestion post. Regardless, it seems that the benefit of Blast Doors' crew loss reduction is quite minor. On top of that, crew are easy to find and aren't very expensive to buy. Relative to the base losses perhaps, the benefit is very appreciable I'm sure, but those base losses always seem so low anyway that I struggle to justify it.
Bear in mind that the two hullmods cost the same amount of Ordnance Points, and that both coexist as available options (they're both available to install from the start of a new game). If I ignore the hull integrity bonus, Reinforced Bulkheads seems the better value option for general loadouts - saving the ship is usually more valuable to me than saving the crew (... uh oh). When you account for the extra hull, Blast Doors is left in the dust - in fact I've gotten to the point that I will only put Blast Doors on with Reinforced Bulkheads to make a ship super hull-tanky.
... Wow. Quite the setup. I suppose this bit is the TLDR. The suggestion that comes from all that babble is this:
Swap the hull integrity bonuses of Reinforced Bulkheads and Blast Doors, so RB gives the +20% and BD gives the +40%. I feel this would make them much more like sidegrades of each other, as they should surely be, and give me a more pressing decision over which is more valuable to me when designing a ship's loadout.