RFguy - try getting answers to the basics BEFOR escalating the suggestions/cost/time.
"With alot of vibration, this might flood the float bowl, or otherwise have it 'not to spec'" - Agreed however may be addressed by the 5 year rubber (engine mounting) replacement question.
"also, check floats actually float the correct height while you are there. " - weight of float (not usually height although strongly related) supposed to be checked at (memory?) 200 hr service interval.
Nev is right with the Dashpot question. have these carbs had an overhaul kit through them ? - 5 year rubber replacement - could be called an overhaul kit but usually has connotations of seats/needles etc and should only be required (if at all) with a very high hours engine, hence my questions above.
Rotax 912, Maintenance Manual Line, Service Schedule, Chapter 05-20-00, Page 9, onwards