We did it on our checkout day, we had originally had an early afternoon flight and changed it to an evening one so we could do this event after it was announced.
We were staying at the BCV, so that helped. I got up at 4:45 to shower and make sure all last minute packing was done. We called bell services at around 5:45 and took our bags down to RAC, and had no wait. We left out carry ons with bell services. Then we walked to DHS and were there at 6:30. I had planned to be there a little later, but for once everything went smoothly in the AM so we were actually earlier than I had figured. But that ended up working out great, since they let us onto Hollywood Blvd at 6:45 and to the ABC Commissary at 6:50. After the event we did 3 FPs at DHS, then walked to Epcot for a little while, then back to the BCV for DME at 4:50. We got to Pittsburgh around 10:30 and weren't home until 1 AM.
I feel it was worth it doing on check out day, if that's what works best in your schedule. It was a fun last day, and much better than our usual just kind of hanging around and watching the clock to see how long until we had to leave. I did have to get up inhumanly early, and I am not a morning person, but for this I was able to manage

. I didn't want to have to hustle back to leave the room and do RAC, so I chose to lose sleep and gain park/fun time instead of rushing back after the event. Since we were walking distance I think we could have just managed and still done breakfast at 10, but I didn't want that added need to rush though the event and have to leave DHS right afterwards. If you are staying away from the BW area it would be much harder to check out afterwards, and I personally wouldn't do it, I would just lose the sleep to do it super crazy early.