I’m a bit late, but still wanted to add a voice in favor of option F for the reasons presented in above comments. Editing and reading sources with many parentheses is more annoying imo than if we can use spaces (see #6442 (comment)).
Additionally, I would be in favor of making any Unary or Vary operator cause the immediately following element to be scripted as well, so that $e^-x$ would work as expected (and we can still write $e^- x$ if we only want the minus sign to be in the exponent): Raising to the power of a negative number should not require parenthesis · Issue #5722 · typst/typst · GitHub