[MVSNYC]

FWIW, this is how it's been successfully executed in the past by auction houses like Mastros, Mile High, REA, Memorylane, etc. There's clear communication at the top of each lot (note the sentence at the very top of each lot page), and the lots are all linked and work together in unison. So bidders have real-time (official) visibility as to which is wining, and then can pivot and change bidding strategy if need be. (Images courtesy of a gentleman from New Jersey).