Here is another one https://github.com/wailsapp/wails powered by Golang, but both of tauri and wails do not support BrowserView like feature in Electron, which means you can not build a brave browser on top of them.
Depends on your skill set, wails maybe better, think building a UI based tailscale app, just make the embed web part display directly instead behind a http.Server with extra 3-5 MB
If I'm trying to bring app to mobile, ionic is my first choose. Like fluter is not the first choice to build a web app. For tauri case, most tauri app shared part is web based, you can just put it into ionic, and deploy for mobile now.
Depends on your skill set, wails maybe better, think building a UI based tailscale app, just make the embed web part display directly instead behind a http.Server with extra 3-5 MB