The snapshot version of Racket (≥ v8.10.0.3) now features Quickscript hooks
Here's a first script (to install just like other quickscripts) that automatically removes trailing spaces on saving a file. Make sure to reload the scripts with Scripts | Manage | Reload menu once the script is installed.
This is a first attempt and I might make breaking changes before the next official Racket release (8.11, probably). So now is a good time to test it and send feedback! 