Why are DLC characters allowed in runs? It seems odd to me that you can pay extra to gain a competitive advantage when running

How exactly is it an advantage?

None of the DLC characters have any benefits that provides an advantage over base-game characters. The closest one to this would be the rapid fire exploit that Bo Katan can do, however Jango can do the same thing.

It's also worth considering that all the main speedrun categories of this game have large amounts of character restricted sections, so most of the run you wouldn't be able to switch to other characters anyway.

I was thinking the advantage would be having the ability to switch to classes you wouldn't have unlocked yet. Niche but to me it sounded odd.