We do it pretty much every trip. Reason being that my family has DVC, so sometimes we'll tack on extra time at the beginning or end of the trip at another resort or split between home resorts. I'm going in August for two extra days without the rest of the family, so I'm jumping from BCV to All Star for two nights. Not a huge deal; I'll throw two nights worth of stuff in a smaller bag and have the stuff transferred.
Personally, here's how I feel: do the shorter stay first and the longer one second so you feel more settled (obviously I'm not doing that this trip but well, that's how it ended up). Have your stuff transferred, go enjoy the park for the day, and if you have any carry ons that you didn't want transferred for whatever reason, at the end of the day, go back to the resort and grab them from storage and grab a Lyft or Uber to your new resort (or gondolas if they're open).
One more thing: I think an earlier poster said you have to let them know in advance. While a nice thing to do, if you forget, just call bell services when you check out and they'll transfer it. Not required to let them know.