@Natanox @librecast @EU_Commission @dentangle regarding big, "fundamental" hurdles: I stumbled over the following 2 issues:
https://issuetracker.google.com/issues/149630944
And: https://mailarchive.ietf.org/arch/msg/pim/ULFLgUK2tBTGkFu6lv9jjknaMsk/
The former finally seems to have a fix but it will need some years until people have updated or replaced their Android phones.
The latter does not seem to have a solution yet, someone needs to write an #IETF #RFC for that.
(and stumbled over many issues with the Linux bridge over 15yrs, but they are hopefully solved now)