Profile of Nubb3r

There's one thing I would like to suggest which is a general redesign of light indirect fire. It's cancer. Moreso in team games but random mortar shells wiping squads are just too much for a competitive environment and this shit happens on a regular basis.

I would propose making mortars more responsive overall and changing them as follows (I'm only looking at non doc, so we can get that straight first. As was said before, one problem with the game in general was it's lack of coherent design decisions and the gap filling with commanders which has done a lot of damage to the balance (see doctrinal flamers, M10 vs Jackson etc.).

All Mortars should have their core function in effectively combating team weapons (forcing pack-ups, retreats and repositions) and softening garrisons/emplacements (but not outright hard-countering them). Further, all of them should have smoke.

OST and Soviet: Ost and Soviet both have a mortar in an early tier and rocket artillery in T4, but that's it.
Therefore I'd say these two mortars should have a "quick barrage" and a "long barrage", where the difference between two barrages is that the long one takes longer to get started, but overall has a way longer duration, like 8 shells or something, making it best suited for anti garrison and anti emplacement (softening them up!). The short barrage should be kept very responsive, since it will mainly be used to force team weapons away and thus it consists of about 4 accurate shells.
For flavour we have the vet abilities which can stay as is, I see no big deal here, except make that flare shell work properly please, since it's been bugged since forever.
The late game rocket artilleries on Ost and Sov should be heavy blob and emplacement/garrison killers, but they are not the main concern here so allow me to skip that part for now.

OKW is in a similar spot with ISG and Stuka, but their timing isn't as distinctively spread apart like for Ost/Sov. I don't know how to fix the ISG without making it UP/OP, so maybe give it slightly more AOE first to make it more consistent and appyly similar changes like for the Ost/Sov mortars.

USF are bloated with indirect fire and I would suggest giving the mortar only the quick barrage option and leave it at that, plus smoke obviously. The long barrage should go into the Pack howie, but apart from this distinction it's getting fuzzy, since there's still the Scott which could be/stay a long range squishy Stug-E type of unit?? This is a part in my proposal that could use some more work, but I can't think of anything good right now. Maybe making the Pack howie a doctrinal airdrop and replacing it's role with the Scott would be good like it was already suggested here.

UKF is also in a wird position, but you already have great ideas for it and I'd go with the little mortar pit that you drafted there. Maybe have the long barrage locked behind being inside the mortar pit and otherwise treat it like USF mortar? There are base howies for late game heavy artillery so I don't see much of a problem there.

That's all the factional indidrect fire units covered, but here's the most important change of them all which should be applied to ALL of them:

Nerf automatic firing! Either increase the delay between aiming and firing, increase scatter, decrease rate of fire, decrease auto-fire range or maybe all of that to preserve their role as anti team weapons and soft garrison/emplacement counters. As of now, they add inconsistency by wiping squads randomly and just increase the "explosive noise" on the battlefield.
I'd hope they'd be more micro heavy and thus more rewarding compared to their passive use, which isn't all that worse than microing them heavily as of now. This is my personal pet peeve with this game and I hope It's okay that I post my ideas here, but since this area of the game needs some major work IMHO, I thought it could be done in a mod and you asked for ideas, so there you go!

TL;DR
Make mortars fit their role (anti team weapon + soft garrison/emplacementcounter) more distinvtively and make them more rewarding to play with and against (by rewarding micro and punishing negligence), all by nerfing their auto-fire heavily and splitting the normal barrage in two distinct versions, each sercing a specific puprose each which have been mentioned above.

cheers!