But how many run cancels can you actually do at a time? Isn't the limit 2 run cancels? If you could do infinity run cancels then I'd think it was something NRS never planned but since only 2 are possible then I think they created this mechanic. Or are more than 2 possible?
On block you get two run cancels. On hit you get one unless you're Johnny (in which case you get two). You can get multiple dash cancels as well but these aren't really useful except for Johnny and Jacqui who can combo with dash cancels.
Several run cancel characters have other ways to get plus frames or staggers that the opponent had to respect which work without stamina though.
EDIT:
For example, Johnny ex fireballs, D'Vorah f112 staggers, Liu Kang f213 staggers, Jacqui literally everything