Some arguments to just “see” these chords as dominants:
1.AnAb7 resolving into C4/6 can be explained as a “borrowed” EXTENDED deceptive cadence from Db. So i find way easier to hear it as a true dominant anyways.
2. it is acoustically a dominant.
Principally in romantic context the first argument seems valid. Problematic is when applied to classical context: because we don’t have extended deceptive cadences there.
The second argument looks valid for any case:
The harmonic series gives priority to the dominant chord as the “natural” state of sound.
If this is not mindblowing for you, please leave the room …!
What do you think?