I didn't try toshy, I had a bad experience when I tried kinto.sh a couple of years back, and I had a pretty clear idea of how I could get what I wanted out of a fully featured keyboard remapping tool under Linux. I initially started with Kmonad, but once I found Kanata, and realized that it had a TCP interface for programmatically changing layers, I quickly switched.

I have a Kinesis 360 keyboard, and my config[0] probably won't work for other keyboards, but it can give you a starting point for your own config.

[0]: https://gitlab.com/spudlyo/dotfiles/-/blob/master/kanata/.co...