Hi again,
Thank you so much for responding! I have actually spent quite a lot of time looking into this, because I flat out refuse to believe my partner and I are the only two folks out there who are playing K2SE+Rampant, and thus want to use the Arsenal. For that reason, I compiled a list of issues, but before I list them, I need to be clear about two things.
First, this is not your responsibility. Obviously. Incompatibilities are just a nice-to-have, and there's no sense in trying to figure out why these things don't fit together just right. I would be delighted if you gave compatibility a bash because I think the presentation of this mod is wonderful, and a modern-looking prettified Arsenal with all the bits shiny and nice is to everyone's benefit, but I understand if you can't be bothered.
Second, my list of issues here is K2SE+Rampant, Fixed+Rampant Arsenal(with your Patcher), which is the important part, but I do run a ton of other mods, too. That means there may be one or two inconsistencies here. I'm working off of an issue list I made for myself, with the parts that I know are specific to my modlist snipped out. I'm pretty confident in this list though.
Anyway, here's what I found needs to be changed. I've listed what's missing from each research by the names of the ammo-categories, but the actual placement of the scaling is probably not super important. The crucial part is that these are things that don't scale as they should.
Bullet Damage and Speed: Missing "pistol-ammo" and "anti-materiel-rifle-ammo" from K2. "railgun", also from K2 (handheld high tech weapon), only starts scaling from tech 6, but that might be fine.
Cannon Shell Damage and Speed: Both are missing "railgun-shell"; this is the ammo type for the heavy railgun turret, which gets no scaling right now.
Laser Damage: Missing ammo-category "impulse-rifle" from K2, only starts scaling "cryogun" and "tesla" from SE at tier 6. It's also missing a strange "beam" category. I think this might be connected to a script intended to boost energy shields, but I can't make heads or tails of (or find) the code for it in K2 or SE. I'm still investigating this one.
Laser Speed: Missing ammo-categories "cryogun" and "tesla" from SE (which there come in at the last two shooting speed techs for 50% per tech level.)
Rocket Damage and Rocket Speed: These are both missing the ammo-categories for "heavy-rocket" and "missiles-for-turrets" from K2.
In addition, K2SE adds a few new turrets which weren't picked up by the new turret-category scaling techs, specifically a high-end rocket turret ("kr-rocket-turret") and a heavy railgun (kr-railgun-turret). These could probably just be added to the rocket and cannon turret scalars. Given how powerful they are, I'd be terrified to see the results. Then again, this is a heavy-duty mod and the new high-tech laser turrets of Rampant Arsenal get full scaling. Generally speaking, I do not really have any balance input here, because heck me, this is all so setting-dependent, but things should scale, and the fact that they don't is driving me up the wall.
If you don't feel up to this, I'd love for you to let me know, because I'm ... like, I'm not great at coding, and I don't know lua. I'm a trash doe who crawls around others' code at this point whilst I learn, but I suspect I'd feel compelled to try to make a compat submod eventually. It would take time, the code would be awful, and it's not nearly as convenient as if you baked it into the patcher tho.
I hope any of this helps, I truly do, and wish you a lovely day <3