And if so…why?
As far as I’m aware it only bans you from matchmaking, both ranked and social. Customs should still be available to join on a friend or host. I however do not know if this bars you from the custom game browser.
Is this a hypothetical question for Infinite? As in, should bans extend to customs? If so, I would say they shouldn’t. Customs is meant to be a place where anything goes. It’s polite to follow the rules of the host, but there should be no obligation to do so. To make up for this, the host should have control over who stays and who gets kicked.