Just to follow up on my experience using the MagicBand+ with children under 13 with the in park experiences like Fab50 Statue Quest and Star Wars: Batuu Bounty Hunters. I thought I had asked and someone was kind enough to reply, but I can't find it, so...
We only did the Fab 50 Quest, but I imagine the experience would be the same for the Batuu Bounty Hunters.
Our son Dom's Disney account was setup and managed by me since he's been going since 1.5 years old. My wife has her own (I can't remember why). He turned 13 last January, so he can have is own My Disney account. Leading up to our October trip, I called Disney and had him split off to his own My Disney Experience account. So now he has his own My Disney account, with all his bands linked (past and present) and our resort/dining reservations were in there. We made sure his new MB+ was paired and connected to his phone. Once that was done, I had him setup a Play Parks account and sign in.
When we got to the parks, the "adults" (13 and over) who have our own My Disney Experience and Play Parks accounts, checked our phones to make sure we were still signed into our Disney World apps and our bands showed they were connected (under bands and cards in the app). When ready to start the quest, we launched the play parks app, signing in as ourselves, flipped through and started the Fab 50 Quest for that park, let the Play Parks app run in the background, and went about our day, collecting statues as we saw them.
The question mark was My friend Dave's son Gibby who is 8. He can't have his own My Disney Experience account because he is under 13. He does have his own phone (without cell service, he just uses Wifi). We found that YES, Gibby could make/have his own Play Disney Parks account (there is no age restriction for this). Being under 13, Dave still manages Gibby's My Disney account under his. What we ended up with was, Parent (Dave) signed into Disney app/account on child's (Gibby's) phone, child's MB+ paired/connected to child's phone, and Child signed into Child's Play Parks on child's phone app. This allowed Gibby to also do the Fab 50 quest as himself. While Dave used his own accounts on his own phone, with his own MB+ to do the quest at the same time.
A few things:
1. I have a spare cell line on my family account (long story), so we put that SIM in Gibby's phone for the trip so he had cell service (Dave appreciated the added comfort of knowing they could call each other if they got separated). So we don't know what would have happened if Gibby only used in-park WIFI (or hotspot on Dave's phone) for his internet connection instead of cellular.
2. Dave stayed signed into the Disney World app on Gibby's phone because there were several occasions the band dropped connection and had to be re-connected. So we don't know what would happen for Gibby if Dave wasn't signed into Disney World app/account on Gibby's phone. Now they had iPhones. My wife, our son and I have Android (Galaxy S22Ultra, Note 20Ultra and Note10+) our bands stayed connected all day (even when I checked mine). We did have a day or two (out of 8 days) where we had to reconnect a band first thing in the morning, after charging the band overnight.
3. We don't know what would have happened if Gibby didn't have his own phone. Could Dave and Gibby's bands have been paired/connected only to Dave's phone to play? But how would that work with the Play Parks app, and collecting the statues in there? It seems like each player needs their own phone/device but we didn't attempt to confirm this.