Like many things in this game, it’s a really dated concept that is extremely restrictive and hindering progression beyond initial intentions.
The only thing you can do effectively is research the same rank or 1 rank higher, everything else gets penalized extremely heavily… 60% is already just not worth it, and a 95% is just cruel.
This severely limits the vehicles you can play and the lineups you can make if you want to actually progress and research without wasting all your time, and considering more and more vehicles get added to the game and we still earn 2014 levels of RP despite over 200 million RP being added to the game, no one wants to lose 60% of their RP.
If you’re researching rank 4 with your rank 3, you already cannot add your rank 2 vehicles despite being entirely valid otherwise, a Stug lll at 4.0 would be perfectly fine with the 4.3 vehicles at rank lll, but not if you want a 60% penalty.
Or a 4.0 KV-1S can’t be alongside your 4.0 SU-152 or 4.3 ASU-57 if you’re researching the next rank.
Back in 2014 where we only have 5 ranks stretched out that’s one thing, nowadays however that’s not the case.
Minor nations especially have been thrown into miserable situations, being given a singular ‘actual’ vehicle in a rank they have to use to research the next rank, even though there are other vehicles here that could have been used like the Type 60 SPRG and Type 61 with HEATFS, but it would be a giant waste of time so good luck to the team when the STB dies because they won’t be spawning anything else.
Even nowadays a nation like Japan has a singular jet at rank 7 which they are forced to use to research the next rank, and even to get to that point they have to grind that one using a 104J, T2 or F-1 which all lack counter measures and aren’t particularly good either.
Even their premium options suck.
I think a 95% penalty is always absurd and always has been absurd, these penalties should not exceed 50% under any circumstance in my opinion, let people play what they want.
So obviously I think we need to expand the research without penalty by another rank to compensate for all the extra ranks that have been added and the heavy compression due to Gaijin’s reluctance to decompress BRs, resulting in a lot of vehicles in close BR being separated by ranks, even rank differences with the same BR.
Or even higher BRs in lower ranks because reasons, but you cannot use the D9 to research but you can use the 109s and other 190s.
The specific numbers aren’t really relevant, they should just not be 95%, absolutely ridiculous.
But you should be able to research 2 ranks higher without penalty, and beyond that the penalty should be within reason and not just remove literally all the RP.