This is just an observation and a comment I touched on in one of my other posts regarding dual boot.
In your firmware releases - I can surmise a timeline like this:
You guys are killing yourselves doing this!
So you released a new Nougat
Then released Ubuntu. And then a new dualos with Ubuntu and presumably the old Nougat.
Then you released Nougat a week later. But you have not released a new Dual OS!
I’d suggest thinking about my comments on Dual booting howto docs
You only need to release a new Nougat, and a new Ubuntu (or let us build our own).
You need to provide the docs and changes/uboot/whatever is needed to make our own multi-boots.
Because, next week someone is going to notice this and ask for a dualboot with the newer Nougat - and you will have to stop and make it.
Then you will release a new ubuntu! - This routine will go on forever!..
NOTE: This ‘routine’ is also much more visible in the VIM1 model firmware releases.