Volksgrenadiers Change

ST44 in a way cost fuel since the require a truck to be set up so that is not the real issue.
Imo some of the issues with them are:

Problem:
The do not follow the weapon profile of assault rifles and have completely different curve from SP ST44 or PG ST44 that confuses players on what to expect from ST44 as weapon.
Solution:
Replace them with single shot ST44 that are a bit worse long range than K98(35-25) better at mid and close (20-10)

Problem:
The DPS curve of squad become different with every model that dies, again confusing players If a riflemen squad fighting a VG start losing entity at the same rate will be surprised to see enemy does better as the fight goes on since the VG squad loses less DPS with every model that drops.
Solution:
Make the upgrade give 5 ST44 so that squad behave consistently

Problem:
St44 can not be dropped and change the relative positioning of infantry fight vs other infantry.
Solution give ST44 VG a timed ability that cost MU that allow them to fire full auto. That would create more interesting game play making the weapon powerful only a limited time.

ST44 in a way cost fuel since the require a truck to be set up so that is not the real issue.
Imo some of the issues with them are:

I think it is apart of it. It's not a side tech but a part of teching. Unlike weapon racks or grenades that are separate research upgrades, access to StGs is incidental.

Problem:
The do not follow the weapon profile of assault rifles and have completely different curve from SP ST44 or PG ST44 that confuses players on what to expect from ST44 as weapon.
Solution:
Replace them with single shot ST44 that are a bit worse long range than K98(35-25) better at mid and close (20-10)

Agreed. I dislike the special versions of the same weapons as well. It's acceptable for the various Kar98ks and Mosin-Nagants for example, but not so much for upgrades. So many different StGs.

Problem:
The DPS curve of squad become different with every model that dies, again confusing players If a riflemen squad fighting a VG start losing entity at the same rate will be surprised to see enemy does better as the fight goes on since the VG squad loses less DPS with every model that drops.
Solution:
Make the upgrade give 5 ST44 so that squad behave consistently

Five StGs might prove to be too much, but there is another SMG that the axis has that might suffice...

Problem:
St44 can not be dropped and change the relative positioning of infantry fight vs other infantry.
Solution give ST44 VG a timed ability that cost MU that allow them to fire full auto. That would create more interesting game play making the weapon powerful only a limited time.

Something like Rear Echelon's volley fire? When a squad has something other than RE carbines, it actually causes suppression. (In an old mod I gave it to Penal Battalions when I exchanged flamethrowers for DP-28s. It worked kinda like PE g43 suppression.)

...
Five StGs might prove to be too much, but there is another SMG that the axis has that might suffice...
...

The idea here is that ST44 on semi automatic mode will work similar to riflemen Garand moving their optimum range to mid from far.

This way upgunned VG are re-balanced as a mid range squad and there to protect K98 VG from being rushed. Enemy squad infantry squad would now perform better against them at far range instead of being no-brainier upgrade giving them bonus at all ranges.

I actually don't oppose a semi auto fire StG version. The thing is, it would end up being a further different version of StG, occupying a role of no other StG. (Although the notion reminds me of vCoH volks. They have a squad member with I think an mp40 on semi automatic fire, set to function just like the others' Kar98ks.)

First mod I made for CoH2 featured StGs that switched to short burst fire at 25+ range. Gave the Pgrens a comparable long range ability on par with a Gren's Kar98k. But anyway, the thing is that currently StGs already give VGs a slight increase at long range.

Volks Kar98ks fire very slowly at long range. This is why the StGs actually increase their DPS at range. Reducing the StG's damage at range would help, but won't solve the problem, due to the StGs staying with model drops.

I wonder if it is possible for Volks StGs to be of a LOWER priority for the squad than their rifles. That way, once they lose two models, their DPS won't maintain.

Five MP40s, even special volks variety MP40s would be preferable IMO. (Perhaps even give them the incendiary nades, and normal volks the potato masher instead.)

The biggest implication would be Volks v Conscripts and the overall OKW v Soviet matchup.