For the purposes of the app, which is managing project schedules and keeping track of each teammate's timetables, it is actually unnecessary for the address field to be mandatory when adding a teammate.
Making the user add an address also slows down the work flow without it adding too much value to the overall planning.
Making address an optional field or even removing it altogether might be better for the app, since it is supposed to be simple and efficient.
Excerpt from the user guide:

For the purposes of the app, which is managing project schedules and keeping track of each teammate's timetables, it is actually unnecessary for the address field to be mandatory when adding a teammate.
Making the user add an address also slows down the work flow without it adding too much value to the overall planning.
Making address an optional field or even removing it altogether might be better for the app, since it is supposed to be simple and efficient.
Excerpt from the user guide:
