Didn't think of that. >_< Tails gives advantages in Ring Attacks and in a few Score Attacks.
So Sonic Advance rules overall should be:
Sonic Advance
In Sonic charts, you may not use Sonic and Tails.
Time DivisionsWhere available, the game's Time Attack mode is to be used for setting records.
On X-Zone and Moon Zone, normal mode must be used.
Rings DivisionsTime Over must be enabled.
Score DivisionsTime Over must be enabled.
You may not enter a Special Stage in the middle of a level.