It's perfectly OK and acceptable for you to bring your checked luggage to the DME bus, for the driver to stow underneath. Please be sure to tip the driver for this service.
If you would like to try to get your husband to not unnecessarily delay you guys and if you would like to try to get him to use the automatic luggage delivery feature, you can show him the following. I cut and pasted it into my word processor, from a Disney CM who explained it all to us a few months back. I made some grammatical edits, but the info is straight from that person in-the-know and not from me:
Here's how the luggage handling works, to give you an idea of the sophistication of it all.
a) Bags are off-loaded from the aircraft. Most of the major airlines drop off yellow tagged luggage at designated drop off points where they are then picked up by a different contractor and taken to a sorting facility. These drop off points are supervised by Disney CMs.
b) Not all airlines use the drop off points. Many of the smaller ones just leave it to Disney CMs working behind the carousels pulling the yellow tagged bags off and setting them aside to be picked up and taken to the sorting facility. DME-tagged bags do not go out onto the public baggage claim carousels.
c) In addition, there are Disney CM's assigned to every airline to catch the bags that the larger airlines missed taking to the drop off point. They also check every unclaimed bag against a manifest to insure that the bags are found even if by chance the guest forgot to put on the tag or it fell off (highly unlikely).
d). All of the bags are scanned (the DME tags have barcodes) when they get to the sorting facility, again after they are put in a locked cage and again when the cage is put in a delivery truck. (3 scans so far)
e) The delivery trucks all have GPS devices and their location can be pinpointed at any time. The computer knows which cages are on which trucks, and which bags are in which cages.
f) The bags are scanned again when they arrive at the resort and again when taken to a guests room.
g) Disney is well aware of where the bags are at all times. As you can see above, each bag's tag is scanned 5 times during its journey.
h) If a bag is delayed the resort will call a central DME office at the airport to begin the process of tracking it down. DME will take the responsibilty of finding your bags for you even if it was lost by the airline and never arrived at MCO in the first place. This saves you from having to wait in line and fill out forms in your airline's baggage office.
(Eric talking now)-- In addition to all of the above, when you check in at the DME Welcome Center they ask how many bags you checked with your airline. If you checked 4 and only three are scanned by DME while still at the airport, they will search for that 4th bag.
If your husband isn't impressed by the above system, then you'll be picking up your own bags. It's certainly not a bad thing -- we all do it at every other airport in the world. But it is such a cool perk. And the way I look at it, I'm already trusting my airline to take my luggage about 1,000 miles, so I won't sweat Disney taking it another 25 miles or so.