Absolutely, it's a pain but worth it.
MDE was down for half a morning on either our Feb or May trip (they are blurring together) and people were pissed (with good reason)... I did have screenshots (learned that tip here) and they let us into the FP queues. But no one else was allowed into the FP queue. Felt bad for everyone trying to use their FP -- and we felt bad for the ride CMs that were bearing the brunt of everyone's anger over Disney's awful IT. And then others had no idea where to go or what they were doing because the entire app wasn't working (map and all).