The code is likely a huge mess, and that is why they can’t give us straight answers.
I’ve seen enough coding projects where we are surprised the code even works. That is D4 in a nutshell. It’s amazing the code works. It’s so extremely flawed… even keyboard inputs are delayed or not even triggered in the game frequently. Like, what?!
If you want to remind yourself what a smooth game feels like, load up D3 and play 1 rift. You’ll quickly be reminded of what proper responses feel like.