Two liberos - questions

[PaREF]

I just took my USAV test and I've spent some time digesting the new two-libero rule. My guess is that I won't see this very often but who knows? I do have a couple of questions and I'm wondering if anyone has been to a clinic or taken the clinic on-line.

1. According to the rules, if the coach wishes to have a libero enter the match immediately after the R2 has checked the lineups in the first set, he/she must be the "starting" libero (the one listed on the left of the lineup sheet). If I interpret it correctly, this only applies to the first set. I think that it means if the coach wants the "second" libero on the court prior to the first serve of the second or third set it is permitted. Is my interpretation correct?

2. Only one libero is permitted in the game at one time. Is it permissable after a completed rally for the "acting" libero to be replaced by the correct player AND the "second" libero replace a different back-row player, essentially, two simultaneous libero replacements?