I just posted to your other thread, but will repeat here also....you can't use DME to the Swan. But, you can book a ride through Mears when you get to MCO. In all probability, you could end up on the DME bus. You can not book Mears to WDW in advance but have to wait until you are there, in person at MCO.
I have taken DME to BCV and made a stop at Dolphin to let off guests. They have to pay for the ride that we get for free.