If it's a simple matter of removing code before compiling then it might be worthwhile, otherwise it wouldn't be worth the trouble.
Maybe in version 4 or 5 we could have "includes" where you link in only the external modules you need, and even user defined functions with private scope.
ESPBasic is fantastic, I just wish I had more time to enjoy it. I have no idea how Mike maintains his phenomenal output with all the updates and bugfixes, but we all appreciate it!