We've done this plenty of times w/o issue - park hopping around lunchtime is really quick - the only time where we had more than a minute or two wait at the gate was when we went a few days before Christmas. If you do park hop to DCA at midday be sure to get whatever your #1 FP choice is ASAP - for example RSR may run out around then. If you have little ones who want to meet A&E that may be your first choice. Another option is once you're through the door at DL, have one person in your party run over w all of your tickets to DCA to grab your first choice FP (for us it's usually RSR), then meet you back at DL. It just means you can't pull a FP at DL until your FP runner is back. I've done a double run - gone through the gates at DL, run to DCA to grab a RSR FP (and WOC FP since it's not connected), then back to DL where I grabbed a FP for something we wanted there, then met up with the family.
If you don't want to do the FP runner thing, starting the day at DCA on a EE day isn't that bad- we will start w/ grabbing a RSR FP, then head over to some of the Paradise Pier attractions which don't open until regular opening - Mickey's Fun Wheel, Goofy's Sky School and so forth so the lines there are pretty short to non existent. Bugs Land and Monsters Inc are usually also very short lines at regular open time even on EE day. The vast majority of folks at DCA open (EE and regular open) will dash to RSR leaving the rest of the park manageable.
But most mornings we want to hit DL first - even on EE days for DL we often go at rope drop and just hit the left side of the park first which is also just opening up at regular open time. And sometimes I'll do the FP runner thing over to DCA.
Have fun!