Disclaimer: I will write a suggestion on this topic but first wanted to hear some responses from the community on the topic.
In summary I want the tech tree research restriction between the different ranks removed. Once you unlock a new rank of vehicles you should be able to start researching any of the first vehicle in that rank. It is extremely annoying and frustrating that when a new vehicle is added, many times you are forced to grind out an entire branch of the tech tree in which you were not interested in the first place just so that you can play the new stuff in which you are interested.
Let me give you an example. Literally in this patch gaijin added the BMP-T. And for some reason they decided to put that thing at the very end of the Russian tank destroyer branch. I have zero vehicles from the TD branch because I am not interested in the ISU-s and the HE canon SPG-s or the missile carriers. However I would be interested in the BMPT, but I don’t want to go back from rank-7 all the way don to rank-2 and grind out the entire branch, waste a gazillion RP and SL just so that I can play the one tank that I am actually interested.
Another very important thing is that everything else would remain the same. Because those restrictions are reasonable and understandable. Yes, you should have X-number of vehicles from a rank before you can go to the next one. We don’t want people rushing to rank-8 and their SPAA or backup tank is like a rank-2 tractor. Yes, you should research the Tiger2-P before you can have the Tiger2-H or first you have to grind out the ZSU-23-4 without the missiles before you can grind the upgraded variant. However, you shouldn’t be expected to grind out an entire branch just because you want to play with one specific vehicle from that branch. Also, war thunder has enough vehicles and nations and vehicle-types so that there is no risk of somebody “getting bored” by allowing this. This change would have zero negative effects.
TLDR: Allow the players to start researching any first vehicle from the unlocked ranks and do not force them to grind out entire branches from the start. Everything else remains the same including, branch restriction within the rank, owned vehicle restriction before you can unlock the next rank, and vehicle rank research effectiveness.