I've had a look and yes, my last update broke it. I definitely tested that update but it's possible I was mistaken, or maybe Stellaris just gives inconsistent results sometimes (or maybe the beta version changed and that affected it?). I now know what the issue was and I've reverted the mod to the working version.

Looking at the files it does seem to be that ship sections are weighted differently for different AI personalities. The missile corvette is just weighted for "preferred weapon type explosive" though and I don't know which AI types have that trait, but I guess that's why some AIs will spam them and others won't.

Thank you for your feedback! It's been very helpful.

Some AIs definitely use missiles on every corvette, so picket bow buff can indeed be useful.

Found that it's missing in options with the following note in errors.log:
[22:39:52][ship_design_templates.cpp:239]: duplicate section template found. Multiple sections are named [DESTROYER_BOW_S3]. file: common/section_templates/destroyer_pbp.txt line: 49

Which seem to be about conflict with the default part, as nothing else installs template for that section here (checked). Not a bug in specific save either, as can be reproduced here with new game + research_all_technologies.

If it works differently for you, wonder if maybe ordering between new/default sections got changed in 2.0.4_beta f368 or maybe affected by something else.

Ah, fair enough. IMO it's a good change though, esp. if PD is underpowered and needs all the help it can get :)
Will be sure to report if I'll spot missile-outfitted armadas on the outskirts of my empires.

I'm honestly not sure, I haven't played far enough in a 2.0 game to really tell either. Stations do come outfitted with some missiles by default though. Auto-designed ships also seem to default to strike craft from what I remember. I think there is *some* relevance, but this was never going to be a groundbreaking change anyway.

Haven't played until late-game with 2.0 yet, but do AIs still use missiles and torpedoes much?
Thought they were kinda all-in on disruptors, making picket sections rather pointless anyway, regardless of slots.