FR has had a way of fastening the mattress to the bunk door since they first started building them.
the dealer that told you to take the mattress off, doesn't know what he's talking about.
UNLESS, FR has stopped providing an attachment system of some kind, which i'm not aware of from any of the 6 Hybrid forums i belong to.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC