If the big architectural differences between Electron and Tauri came out in Electron's favor for your project (i.e., if differences between rendering engines were a real problem in practice), then I'd say it would almost certainly be a mistake to choose Tauri just to avoid having to do FFI. Of course, if rendering engine differences aren't a problem in practice, then the choice is much lower-stakes and what you're currently doing will probably be fine.

I totally agree. If it turns out that we are getting too many bugs because of the different web engines, then we will ditch tauri for sure.