Some things I noticed:
- It doesn't work when you run the game with D3D9Wnd. How does it look for the game?
- The "Exit remapper" option always appears in the bottom right of the screen, regardless of the actual placement of the tray button
- It doesn't check against blocking keyup/keydown events (e.g. to prevent pressing a second space while the first space is still held) except for only one time, beaten by an extra KEYUP, which is forbidden on TUS.

While it might be a good idea, it will never be integrated with the game as much as RemapKeys does it. RemapKeys hooks into the game's own key-processing code and augments it, which provides sync (unlike all external apps which are asynchronous, and if there's some lag in the system, there might be severe delays), and follows the game's behavior: for example, if you remap Space to Tab, then Tab will work as a Space when there's no worm to select, and will still work as Tab when in worm-selection mode (thanks to latiOs for the tip), as well as proper chat detection (no need for the convoluted PageUp/PageDown listening: the game tells us everything). It will not be possible to (easily) implement anything like this in an external application, you'd have to inject something into the game anyway.
If you're having any issues with the RemapKeys module, just ask me, because I'm quite sure you didn't correctly set it up.