On our 2011 Sunseeker the LP/CO detector has power from the battery disconnect switch and will drain the coach batteries if the disconnect switch is not turned off. The antenna booster needs to be switched off. Neither uses much power but over several days it adds up.
Turning the disconnect off is the way to go, but you could put an ammeter in series with the positive battery cable and see if you have other drains. If you do, pull the fuses one at a time to find it.
I don't know, but the Bidirectional Relay Delay controller may have a small power usage. There’s 12 volt power to it when the disconnect switch is on.
2011 Sunseeker 3100
1997 Pathfinder Toad