We haven't begun work on the Linux version of the browser yet. We will need to significantly expand our team before undertaking the development of a browser for a new platform.
The macOS browser is based on WebKit. If the team can’t justify the Linux version yet, changing it to a whole different engine (and one which is notoriously hard to embed, by admission of Mozilla itself) is even less likely.
Thank you. Lots of love to Kagi, though I'm not a paying user yet but I do love what you folks are doing and want to f*ck Google.