[Tiki-users] Dropping abandoned Tables in Tiki-Schema

Hello all,

I want to update my slightly outdated Tiki 8.2 installation to 21.2 and 
find some error message pertaining not yet properly converted tables (to 
uft8mb4). I'm using MariaDB 10.5 BTW. I *believe* it's not that 
important mostly, but want to be sure.

Well, my best guess is those are leftovers from features which have been 
dropped (like galaxia.* or tiki_eph), or they somehow came out of use? 
They have in common that they are empty and that they have the outdated 
charset/collation or perhaps special names (zzz_unused*)

Long story short: is there a positive list which tables can be dropped? 
Or is it 101% safe to drop tables which are not included in tiki.sql? 
(Theoretically tiki-install.php could just rename things or create 
tables by other means?)

TIA, Manuel