@avenyap(View Post) Slowing down is possible, but speeding up is not. Your current framerate(Without capping to 61!) is the maximum speed TPT runs on. Slowing down just needs the capping to be a variable. Possible, but not necessarily useful. You can spam the F button to move a single frame forward.
You can already change the fps cap. tpt.setfpscap(number) in console setting it higher than 60 will only speed up simulations if you can already reach 60 on them anyway.