Some years ago there was a tool called ShortKeys which I used a lot (https://www.shortkeys.com/). The tool replaces given keystrokes with other ones, or even with full text strings (inc multiple lines) etc.
So for example one would type
#GB would be erased and instead it would type
God Bless in place of what was there, automatically.
It would be great to have such a tool for Linux. Are you aware of any?
My main use would be console/terminal-based. So for example, working in
vi I would type some specific keys which are picked up by some tool and auto-replaced by a specially desired text.
vi can do something like this natively, that would help too.