> 4. Adding their own UI. In the cases where the current inx based UI falls down (conditional values, and many more) the users want to able to use, say, Kivy or even tkinter to do dialogs. This is super hard and only one I know that works is the very recent embroidery extension which needs own installer and is so complex I can't follow it.

Oh dear!  Sorry it's so confusing.  As I think you understand, trying to get a cross-platform UI working is quite difficult.  And for translations, we had to completely ignore inkex.localize() in favor of bundling our own translations, because we can't get our translation strings into inkscape fast enough.

On the plus side, we handle units and viewbox correctly and we're 96dpi compatible already, so no work needed there.  Thanks for all the work you're doing!

We're happy to answer any questions you might have on how Ink/Stitch works. I follow this list, if somewhat slowly at times, but the best way to reach us is to file an issue (github. com/lexelby/inkstitch).