“Replace All Misspelled Words with Topmost Suggestion”

[Cletos]

Maybe to make Notepad correct an entire file / text without interventions would be great.

https://community.notepad-plus-plus.org/topic/25427/how-could-one-use-a-spell-checker-for-a-portable-notepad/5

[Predelnik]

It won't be particularly hard to implement but it seems to me more suited to a separate script rather than plugin in text editor.

[Cletos]

Sounds great! But why?

[Predelnik]

Because you just operate on the file and have no need to do anything visually, e.g. it makes more sense to work as the command line tool like:
fix_words.py text.txt -o fixed-text.txt

[Cletos]

OK, so because there is no intervention / nothing more needed, than just to initiate the correction of the entire txt.