I think that the commonly used refactoring functions would make a big difference and right now most IDEs are pretty bad at them (especially across all the languages jetbrains supports):

  - rename variable/function
  - extract variable/function
  - find duplicate code
  - add/remove/extract function parameter
  - inline a function
  - moving code between classes
  - auto imports

Others are used more rarely and can probably be left out but I do think it would save a lot of tokens, errors and time.