Hello,
I am one of the developers of the sfos-ja initiative. Currently I don’t have any Sailfish OS devices to develop or test patches on to keep developing the keyboard, but with a bit of help, I could fix the patch or make do a pull request to an already existing one to keep this project afloat.
I could also invite developers willing to take over the development into the sfos-ja github organization. Let me know if you’re willing to assist me in this.