I've run deso 3 times now and i think you could spend a life time exploring side canyons and looking at petroglyph's, theres just so much down there.
Ran it the lowest a little bellow 2000 and it was fine, coal creak was preaty bony though.
Shuttle is long and worth paying river runners to do, rough road to sand wash.
Hit it late may when it was peaking at 16000, no bug problem and white water was tons of fun! Sounds like if there are mosquito's sand wash is the worst.You can reserve a screen tent @sand wash through rec.gov if you want.
River maps makes a great guide for this section, at least scout joe hutch canyon, they list a couple others that are worth a scout, depending on water level. Use good judgement, you are a long ways from help on this section!
Think even if there are some bugs you will still have a great trip, In my opinion deso is preaty awesome!
" I wish I were a headlight, on a North bound train..."