Thing is westernization in game is weird regardless of pacing. It doesn't boost tech levels just remove penalty and give neighbour bonuses if you hadn't managed to get most of it anyway. It seems to want to strike a middleground between actual westernization(that is replacing part of cultural, societal, economical and such values for western's to thereby be capable of easily 'catching up' and learning from the then more similar countries) and modernization(keeping up in technological development and implementation regardless of how precisely) but lacks several advantages of either while at the same time the disparity is far greater than what would be historical so it has to be easier than them if most of the world is to be even relvant(not even playable or important).
Really I have been wondering for the longest time on seeing how hard it would be to set up things so that westernization is similar to what is right now in game but also putting you up to 90% or so of tech level while adding specific reforms that every country has to go through to keep in tech to represent unifications, nation'states and so on. Would require setting up a lot of different paths and base requirements to meet at least the general circumstances of countries world wide but it would make for a far more interesting game even in Europe and have the playthrough of countries be more distinct as right now you have basically native americans, Ming, hordes and everyone else.
Thing is, the "answer" already exists.
It´s Victoria 2´s system or an improvement of it. It would also allow for western nations to also be assymetrical (because seriously, Portugal or Russia didn´t really have tech 32 32 32 like UK had).
The problem is, Vicky 2 has WAY fewer nation tags. It allows therefore to add complexity in areas which EU4 kinda can´t. Or maybe you CAN add that system but it was not the philosophy of the game.
Add to that how Literacy exists and works... and OMG I want Victoria 3 now :/
IMO the whole social and economic system of EU4 should probably be merged into one system, and military technology have ANOTHER system.