Pasting blocks into right indentation or reindenting entire blocks too. So I am glad you agree it's simple to do any of these even with significant whitespace ;)
I wouldn't know about other editors, but I'd be surprised if it's not so in every one of them.
Where indentation really matters for temp debug statements — you want to enter a block unconditionally or skip it unconditionally — there are other syntactic tricks like add `True or`, `False and`, return, continue, break, semicolon, etc. But these are all temporary examples you are giving, and this only matters if editor is not supporting you.
And that's my point: these are trivialities and I can't stop being perplexed that people get so fussy about it.
I am not sure how git plays into this? It works exactly the same for Python, it's not like Python is bf with space as the control character.
Moreover, the ] modifier before p or P (paste below or above current line) adjusts the paste to the indentation of that current line. It takes next to no effort to copy and paste some code to the correct indentation.
Backing changes out nowadays is done with "git checkout --patch".