No functionality is taken away from the SL 1642AI when one of the stagebox modes is used (simple stagebox or I/O monitor mode). All outs are working on both mixers, also the aux outs. Just the mono out of the RM is not used, as the SL can not feed it. You will need an AVB option card for your SL (the RM comes with it) and an AVB switch (there is nothing else available than the MOTU AVB switch). The AVB switch also makes remote control possible, so the musicians can control their mixes themselves.