I've been using the Notes section a lot in my planning. I've included notes for flight times and approximate DME pickup times that can be updated once we know the actual times (especially helpful since our group is flying in and out on various days), etc.
I've also used them for day-long plans like Food & Wine Festival, our day at Blizzard Beach or the evening we're heading off-site so that the group knows what we're doing that day despite there not being dining reservations or FP+ for those periods.
And once we're on the trip, we can use it to set meetup times and places if we want.
While the phone app will properly "sort" the Notes by time, I've found that the DME website always sticks the Notes at the bottom of each day's activities.
-Rob