We've only had 1 trip in our '04 261T, and definitely need to do something about that bump. My wife cut up some "egg crate" foam and put 2 layers under that area, but it's not enough to help.
Building up the low area on the end does not address the problem. The problem is the 1" trim piece that will still be there, stickup up into your back. The mattress isn't firm enough to mask it.
I'm considering building up the low area (to match the height of the rest of the bunk), scrapping the mattress, and going to an air mattress. Like one of those dual-twin "Quick beds", since a standard queen airbed is probably too long for the tenting.
thebrakeman ('70), DW ('71), DD ('99), DD ('01), DD ('05)
2004 Surveyor SV261T (UltraLite Bunkhouse Hybrid)
2006 Mercury Mountaineer V8 AWD Premier
Equal-i-zer WDH (10k), Prodigy Brake Controller