(Author here)
Feel free to ask any question, I'll be happy to answer them :)
How does this integrate on Linux? I took a minute and couldn't find that information on the website.
Espanso currently supports X11-based linux systems through the X Record Extension [1] and libxdo [2]
That said, I'm currently working on another engine based on evdev that could be able to support also Wayland systems.
For the linux install see also: https://espanso.org/install/linux/
[1]: https://www.x.org/releases/X11R7.6/doc/libXtst/recordlib.htm... [2]: https://github.com/jordansissel/xdotool