In addition to the system detection in system.sh, where you specify the detection method and the capabilities, you'll need to decide which distro (and flavor) you support and set the debian/ubuntu_ver. The platform flags in system.sh also have to be able to differentiate the platform so that different packages can be built with the proper make/cflags/ldflags parameters. Some emulators have makefiles that take into account the SBC platform and set compiler options themselves (i.e. Amiberry).
You should also take a look at _mapPackage in helpers.sh to make sure that kernel headers package are properly detected and installed. Armbian has a different naming strategy for kernel package names than Ubuntu/Debian and they also provide different distro options for the same SBC (Debian/Ubuntu flavor).
Lastly, you'd need to check what packages should be enabled via each package's flags and make sure they're working properly.
