Multiple accounts is supposedly in development/beta - https://help.hipchat.com/forums/138883-suggestions-ideas/suggestions/2716912-let-me-be-a-member-of-and-sig

Multiple accounts is supposedly in development/beta - https://help.hipchat.com/forums/138883-suggestions-ideas/suggestions/2716912-let-me-be-a-member-of-and-sign-in-to-multiple-acco https://help.hipchat.com/forums/138883-suggestions-ideas/sug... but yeah, they waited way too long to implement that.