We did that once - our first trip to DW. A CM at Epcot TOLD us to do that. We had no idea what we were doing and simply asked her advice on how to go about getting over there. We had paid to park at Epcot and then had an early dinner reservation at chef mickey's. We walked over to MK for a few hours after that. She said it was absolutely expected and allowed. Guess we won't be doing that again!