Sorry for the late response, but it's easier to just say no so that we don't have to verify that all the load times for everything are the same, and i can't think of any reason why there would be a need to use ctgp-7
i'd like to re-open this threat, because of mario kart wii, which made a specific ruleset for the usage of their ctgp version - also because i had planned to do a "all mario karts - all track" marathon in the near future and got some people asking exactly this question - i know it is at the moment not allowed (and i sadly don't have ctgp7 yet - so i can't say what the options are) but if the moderation team could set on a set of rules regarding ctgp, that are pretty much identical or near identical to regular game load times. it would probably help some people.
Still no. If you want to do a vanilla run just play the vanilla game, why is this even an issue