I'm working on a Sailfish port, however this depends on three things which are out of my control: a) Official python support (not a blocker, just prevents store distribution) and these two feature requests:

https://together.jolla.com/question/...-destinations/ - Without this it isn't possible to send notifications to the Pebble except in a very hacky way.

https://together.jolla.com/question/...-music-player/ - Without this it's impossible to control the music player from the Pebble.