I don't mind reflashing my 32GB for a shared Sailfish + Debian partition, but I will avoid flashing over my android installation.
how large of a file size would a "universal" linux.img be, og can I merge them by myself?
I honestly dont mind wasting a handful GBs to get this up and running.
Alternatively, I think it should be possible just to restart from the old shared installation, and update sailfish from 2.1 to 3 from within the OS, but that is just a bit time consuming.