That is, the best way to deal with apps being too clever about rich text, is to never give them rich text in the first place.

Notepad is for multi-line text.

EDIT: While the address bar trick may be slightly more convenient than Win+R (and the easiest thing to do on Linux), keep in mind that whatever you paste there will likely end up recorded on someone else's servers. I bet this was a major driver for integrating previously separate address bar and search bar, and adding "search suggestions" function...