Comment by millzlane
Espanso looks promising but Atext (paid) fits niche very nicely for me.
With atexts gui it makes building new entries easy. I even have a keyboard shortcut to use highlighted text to quickly make a new entry.
I have used it to write emails, make automation's for certain websites that take keyboard shortcuts. I use it to build query searches for certain websites I use frequent (kinda like firefox back in the day).