It is not clear to me yet how will proceed with the 2nd gen yet. After the X1 1st gen port is done, it is actually more logically to port to the X3 1st gen which is very similar (both hardware and software).
As you say it could be easier to port X3 1st gen than to X1 2nd gen - but that would lead to another rockbox port to an outdated device.
IMHO it would really be nice if rockbox could support a buyable device - and not only old ones
I'm still searching for a more modern device which I can buy
as replacement for my iPod classic/video - thinner, faster, with bluetooth, with reasonable storage, similar or bigger screen size as with the iPod's and of course with the possibility to use rockbox (at least in not so long future).
I don't know how long the Fiio X1 2nd gen will be on market but currently I think this could be such a device - if a rockbox port is close in hand
And I'm not sure if I could live with the original (limited) firmware