Imo sidetech can easily work for the soviet. Side tech allows you to choose if you want to invest into a unit or not. And since Soviets have so many good doctrinal option imo it is the way to go.
The player will have the option to either improve his core units with side tech or invest in doctrinal units.
The current changes to T2 (cheaper) do not make more attractive simply because T1 offers to much for too little. Instead they allow back tech solidifying T1 as the best option.
If one lock penal power behind side techs and upgrades T2 will become more attractive with out leading to maxim spam.
Or it could completely backfire and move soviets back into call-in inf spam meta due to inefficient resource having to be pumped into infantry to be competitive, forcing tech delay every single time.
Keep in mind that for side tech to be a viable option, base unit also needs to be cost efficient and viable option, otherwise you'll just repeat cons again.
Trying to force side upgrades with excuse of them having doctrinal infantries is extremely bad argument, given that current penal state is a direct response to allow soviets to play without call-in infantry doctrines.
T2 will never be attractive option if maxim remains inefficient and con 7th man comes so late.
Best case scenario, meta will shift back to M3 flamer into cons+snipers into guard spam.