Adrian,
The only prohibition in the rules is that you can't play in a stroke play and a match play event at the same time. The Rule 32 states that Stableford is a form of stroke play so there should be no problem other than everyone has to hole out in the main medal competition so there would be no picking up as there usually is in Stableford. There are some complications for penalties such as violations of the 14-club rule, but they can be worked out.