As long as the program accepts keyboard input or clipboard pasting, espanso should work correctly. There are some programs that behave a little bit differently (such as Thunderbird on Linux), that require a couple of configuration changes to work as expected (for example, slowing down the injections if the program is slow to process input).
Happy to answer any other question :)
It's 2021 and some people still don't separate UI into its own non-blocked thread.
E.g. When crunching a big dataset in QGIS (on Win10), every digit I type into "Classes" box [1] blocks everything and I have to wait.