If the net result is that ITU/DTC are already must-haves for slower/ballistic-focused ships,
ITU/DTC are must-haves on larger hulls by design, though. It could've also been handled by making them built-in on cruisers/capitals, but I like the idea of allowing some room for more specialist builds that don't use those.
The reason is that large ships generally need longer weapon range to avoid being easily kited down by anything smaller and faster. Basically, without those hullmods, large combat ships are in a very precarious position, design-wise; near to being obsolete. I don't think you could make the same argument for UI, it's just not as fundamental, and I'd just as soon have fewer must-haves.
Right now, ITU is already cheap enough in OP terms that it's mandatory (IMO) on non-SO frigates
Probably an argument in favor of the frigate-sized ITU being underpriced. Two points is very low, and looking at the progression, it's out of line. I think when I was pricing it, I wasn't thinking that 10% was as impactful as it is in practice. So: raised the cost to 4, which is in line with the progression.
I'd argue that with weapons like the IR Pulse Laser, if you're relying on them you actually lose less range on an SO ship (500>462.5) than on a ship with Unstable Injector (425), so there's no real reason to use UI on those ships at all.
SO has a bunch of other downsides, though.
I'm coming at this from the angle of having designed a fast midline faction with lots of hybrid slots and wanting energy weapons to be competitive on them; perhaps that's not applicable to vanilla ships, but I think it solves a lot of edge cases and feels cleaner than the current percentage approach.
Hmm - a couple of things. One, energy weapons and ballistics are not very competitive with each other in direct-damage-dealing. Energy weapons are all-around worse at that, which is compensated by ships using them having better speed (to counter the lower range, again the see-saw of the two prime stats) and flux dissipation. The only way energy weapons really compete *in the same slot* is when they provide some utility in a way that ballistics don't - Ion Cannons, Ion Beams, long-range PD (yeah, a bit of a niche case), beam weapons (range + flux trading), a Heavy Blaster for armor cracking, and perhaps a few other things.
So, if you're putting a hybrid slot on something, "ballistics go in it" ought to be the baseline expectation, with the slot type providing a bit of flexibility for utility. That's just the grain of the weapon design. This is also why hybrid and universal slots are used sparingly in vanilla.
Two, "fast ships with hybrid slots" is a potential warning sign. You've basically got fast ships with ballistic weapons, then, which could mean they're going to be overpowered - or at least hard to balance - due to a combination of speed and range. If really depends on where their speed and mobility systems (if any) place them, relative to say midline ships (if you'll note, those tend to have maneuvering jets, which while having good utility, aren't an overwhelmingly good mobility system otherwise).
If it were me, I'd probably look at a built-in hullmod as a way to make ballistics and energy competitive on your ships. If a general-purpose hullmod did that, it'd probably break things. But with a built-in, you have so much more freedom - for example, you could increase energy weapon range, or reduce ballistic range, depending on how fast your ships ended up being and what you wanted in terms of balance.
And 600 range also includes a large number of low-end small ballistics.
Yeah, that's a bigger issue. I dunno though - on something like a Lasher, is that really a problem? I guess it might be a minor buff to larger ships that use small ballistics, but given that those ships have short ranges as it is, UI would give them an option besides ITU, SO, or simply being second-best.
(I meant more in the sense that small ships using those weapons would also take UI as a no-brainer choice; i.e. it would harm overall build diversity.)
On a side-note, how exactly do multiple flat and multiplication modifiers interact?
Like most difficult case - 1000 range beam + UI + Implants skill + ITU(Capital) + Optics + SO + Electronic Warfare.
Generally, percentile reductions are multiplicative; cases where they're not are either oversights or something where it wouldn't make sense (such as, say, the hazard rating of a planet). Percentile increases are additive. This prevents both increases and reductions from stacking out of control.
The order is: percentile increases, flat modifiers, then multipliers. The "range mult after cutoff" modifier is special and applies after the initial range calculation.
So for a beam with UI, it'd be something like:
(1000 (base) * (100% + 15% (gunnery) + 60% (ITU)) + 200 (optics)) * 0.85 (UI) * <whatever EW happens to be>, then modified by SO. Which you couldn't put on a capital ship, but that's beside the point.