I would personally like to increase the variable speed range quite a bit, preferably by adding speeds above 2.0 (2.1 to 3.0, for example... there is actually one podcast I prefer to listen to at 3.0 because, at least to my ear, it sounds like it plays rather slow at "normal" speed). Only being able to use one custom variable speed can be somewhat annoying for various reasons.
This is separate from the request to have different variable speeds for different feeds because this would be universal and provide greater speed customizable. One way I could imagine it is by giving users the option to define an additional variable playback speed range... so instead of just adding, say, 2.5, I could input 2.1-3, and then I would be able to choose any speed within that range...
Or something like that...