Actually I looked up SRB2 2.1 Mods, and I found a mod called the past and a few other mods. But I'm glad you know about it then.A bit of a weird one considering it's nature, but SRB2: The Past is a pretty great one due to how comprehensive of a collection of old SRB2 content it is, and how it makes them more accessible due to the better controls of 2.1 compared to those older releases. It even has a couple extra merits with stuff like the beta quest, letting players take a peak at the prototype levels (like Mine Maze and Rocky Mountain) that went unused.
Explain to me on why you don't have Silver, Pointy Sonic, Shadow, Inazuma, Dirk, FSonic, Metal Sonic, Metal Anyone, Orb, Ray, and Jasper right now . Joke aside there are so much characters for 2.1 out there (Weirdly almost/is shorter than 2.2's characters slot even though the game was expanded for 5 years) that are very fun! The characters I listed I personally recommend checking out as I have fun more with them!These are the mods I already have:View attachment 62948