I understand the devs reasoning for no longer including official circuit maps--Sonic is too strong in them--but why can't a race server simply default to randomizing which character each race lets the players use (of course, with a console variable to disable this and allow free character choice).
I'm a very big fan of the basically-dead Motorstorm series, a series which I feel has surprising similarities to Sonic in that both are series which emphasize complex multi-layered level design combined with distinct characters (vehicle classes in Motorstorm's case) which have distinct routes throughout each level to take, in genres that normally don't do that kind of thing. Bikes and ATV's could take thin higher routes, rally cars and racing trucks took flat middle routes, and big rigs and monster trucks took bottom routes full of slippery mud and other things the other classes couldn't handle. Of course there's the problem of balancing, a thing Evolution Studios got around by simply having the game randomize which classes players could use each race (at least in Apocalypse? I think the others did too). Like, Pacific Rift had the exact same problem as SRB2 in that Monster Trucks IIRC were just blatantly better than every other class in almost every way, but it wasn't a problem there since oftentimes you just didn't get to use them. So, if everyone has to play Knuckles in a race, the problem of Sonic just thokking his way to victory is completely sidestepped.
And while you may say that limiting player choice like this is bad, I feel that the strength of Classic Sonic--and thus a strength of SRB2--is the variety that the multi-layered level design and highly differentiated routes each characters can and often must take. One netgame race you're flying high as tails--later on the same course you're instead gliding and breaking through walls as Knuckles.
I dunno. I just love the idea of racing people in this game on dedicated maps for it and yes, I know, SRB2 Kart exists but...I wanna platform, ya know. I feel there's a way to make it work.
I think the concept of Race in general ought to be reconsidered a little bit. It's inevitable that some characters are going to be stronger than others on a level, and I think forceskinning random characters isn't the most graceful solution.
But I do think we can draw some inspiration from SRB2 Kart and the way that the Mario Kart formula handles items. Random monitors would be of much greater value if the items they grant is dependent on that player's current placement within the level. E.G. players leading would get "weak" items that don't advance their placing very much like 10-ring monitors and force shields, whereas players in last would get "strong" items like teleporters and speed shoes, etc.
I don't know if that would be enough to fix circuit, but race as a mode is really struggling in general right now, and changes like this might help increase its popularity.