This is like the old Time Control Remote mod, except less buggy. Thanks for making this!
Speaking of which, would it be possible to make a "Time control remote" thing for this? Basically it just adds a craftable remote that changes your tickrate (eg. the "Fast motion remote" sets your tickrate to 40, while the "Slow motion" one sets it to 10). Of course the remotes should only be usable in Singleplayer.
The main reason I'm saying this is because I feel that it would make this mod slightly more user-friendly for some users (and not require cheats to be on) and might get more people to be aware of this mod.
I don't know, It's meant to be a tool mod. You can use it to build your own map/minigame/mod, but not meant to be used in survival.
You can use a few command blocks to make an item that changes the tickrate, you can also use the key bindings to change the tickrate without using commands.