Imo the issue with OT and research is practically the same.
Both concepts and the systems the use are problematic fundamentally. OT can make far better ordnance from scratch and do it for free in exchange for time and some chems from research/medical. Research can make stims from scratch, provided they get points and with some luck, that can turn the game around in 30 minutes.
Both can turn the game around in the hands of the right players and they can make the game unfun for xenos. OT by making ordnance that you can do nothing against, say a maxcap rocket that gibs everything in a 4x4 radius. Research by making stims that negate stun, which is the base of the kits of many castes therefore making the game unplayable for them.
The easy choice to solve the issue is to remove them but I don’t truly see this as a solution. Instead OT and research can either be nerfed to the ground or reworked fundamentally. There’s nothing creative about nerfing them, it’s already hard to locate the aspects of the role that need nerfs and by doing so you essentially waste their role in the game which is not ideal.
In my eyes both roles need to be reworked in terms of what they offer to the game.
For example OT can be turned into an ordnance expert that excels at making improvised explosives by using existing standard issue ones and his engineering knowledge. I already begun making sprites for this idea although slowly, I think it’d be a good fit for CM both in terms of balance and concept, since all that changes is how you use existing ordnance.
Research on the other hand is a more tricky one that I have not thought of very much, but the idea is the same. Just change the way it contributes to the marines, and in a more moderate and balanced manner. The how needs work but this post is just food for thought.
I think this is the direction effort should be going if we are ever going to solve the issues. Feel free to brainstorm below. Maybe something good will come out of it.