I was told by the CM on the phone that it is not necessary to link it. You just need to have the confirmation number with you.
Is there a reason to put it in the notes?
Only to have it available in
MDE along with your other reservations (FP+, Dining, tours) so that you can see everything in reference to each other. Be Our Guest lunch FP+ is a perfect example - because it does not show up in either the dining reservation system or the FP+ system it is "invisible" to MDE.
You can then plug in items like :
"Early Bird" bowling times at Splitsville (fun !)
Offsite dining you want to do.
Offsite experiences you want to do.
Spa visits.
and other things, all available in one view and shown in reference to each other.
It also helps to avoid time conflicts. For example, last week we had a BOG FP+ for lunch and Beaches 'N Cream supper reservation. We knew we would still be full from lunch when we showed up at Beaches, so we decided to cancel the supper reservation. I saw the conflict by having both listed in the app, and canceled the supper reservation from the app too.
Hope this helps.