After picking more satsuma fruits on my trees, now I think I figured out what variety the mystery satsuma is.
I have about 5 fruits that are ripening now and picked some to do a taste test. The satsuma in my original post above (Nov 2019) is a Dobashi Beni.
I picked fruits from Owari satsuma, Ponkan, Gold Nugget, and Dobashi Beni for the taste test. My favorite after the test is as follows:
1. Ponkan
2. Dobashi Beni
3. Owari
4. Gold Nugget - N/A, was not fully ripe.(need to wait until end of Jan/Feb)