Units can work around this for now by assigning one or more registered scouters in the unit as a Key 3 Delegate. That’s the functional role I have been assigned as an ASM, and I am able to assign MBCs to our scouts.
Once the issue that’s been noted (e.g. by Donovan) has been fixed, unit Key 3 will be able to further delegate this ability.
As an MBC, I also have a button I can click to connect to a scout (given the information in the second box). So, I think scouts/parents MBC can also work around this by providing the needed information to the MBC.

