Hi, I assume the part before the / is the name of the snap, is that correct? so you want 20 and 22 tracks for 4 snaps?
And usually, track versioning is used by snaps that depend on features of the base system. Is that the case here? (i.e. what happens if I install the core22 version of ubuntu-frame on a core20 system?)
having those tracks will allow users to only have a single base snap on their system (Frame often gets deployed on limited resources)
Frame depends on the graphics userspace drivers to be provided through the graphics-core20 content interface - some userspace may only be available for a subset of the bases, ABI-wise
The remaining three are supporting snaps to which the same reasons apply.