As it is right now, the no of items, is displayed on every item, once the numbers get big enough they overlap and reading the output is hard.

What i would suggest having the chest still display item numbers, until more than 64 is present. Once there is more, just show that there is "64+".

Now if the player needs the item count, there could be a possibility to select that slot and show the information about that slot in the chest GUI. ie. example made with paint

I am planning to do this similarly the way AE does, seems to be nice, don't you think? :P

That is also a possibility, which ever one is easier to code and/or is more lightweight should be the one, i'm just trowing in some bones :)

unfortunately until now I not find a way to change the "vanilla way" to render itemstacks, I will keep you updated, ok? :)
also, you want to be tester of it? you helped me a lot.
if yes, could you please tell me your nick name in Curse Forge?

Sure, i dont mind, its the same as in here: SteelShot

been implemented since version 1.0d