If you use decent quality binding posts don’t see it would affect the sound quality that much. My crossover board is all hardwired, but don’t plan on needing to disconnect the crossover from the speakers. Though I’ve thought of splitting the input to the crossover for experimenting with multi amplification. If I did, Id use either GR tube connectors or high quality binding posts.
Never seen anyone put no rez on the braces, as long as it’s all glued up solid, don’t think it would improve anything.