is your rubber roof FULLY bonded to the roof, or do you have a few loose spots as the glue breaks down? (common prob, seen many rv roofs “fluttering” as they pass me on the hiway at 75mph…)
only problem i could see is if your rubber is not stuck down 100%, may be too flexy, too much movement. alsans itself will bond to practically anything, but it has to have a reasonable solid base for it to work. and you would not need to remove any details on your roof, you cut the rubber around the flanges instead and leave everything where it is.
i would suggest try it around a vent or something to test it, but as it don’t come in small amounts it’s kinda impractical.
if you have probs with your rubber roof, try this caulk, we have found it to be one of the better, if not best epdm caulks out there, Carlisle lap sealant, still will have to maintain every couple yrs or so…