Its sort of impossible for it to be good as 4.4 and bionic are out of whack and some of the libs/software require a newer kernel.
Prob would of been better to of made xenial.
Its a bit like the above Buster server as yeah it will work with 4.4 but its not the kernel generation for that release and you will find problems.
It seems to lag updates to the radxa apt if even if they are updated, but guess its easy to apply any rootfs to the current working uboot/kernel