depends on what you call off roading
if you thinking of travelling many thousands of miles on washboard corrugations lots of luck finding anything that will stand up to the task
my bike carrier custom designed for just a purpose saw me almost loose my 1k v strom off the back - it was a failure of the tie downs not the carrier itself but if your going to keep the bike on, everything has to work
and most importantly it has to work once it had a good bashing around
no point getting there to find you cant load or unload the bike because of structure or component failure, and include dust ingress into the electrics as a common problem