I may not even need OCR - I could trigger keystrokes CMD+A, CMD+C to copy the whole page and do it that way. Still not quite what I want (inline checking) but doable. That said, I didn't have much luck getting spell (which was recommended elsewhere on the forum) as a solution. I downloaded aspell (via HomeBrew) and can run it in the Terminal, but can't seem to to get it to work inside KM. I was referencing this list - Check the Spelling of Text on the Clipboard - #2 by ccstone where @ccstone suggested it could be done using a simple shell script of aspell list | sort.