I do not see a problem with that, surely it is within most peoples capabilities to change a wheel? unless there is more serious damage preventing the car from being driveable immediately after?
This is just an extension of the "extra" charging, much as charging to bring petrol if you run out.
If you have good reason that you cannot change a wheel, such as registered disabled, the it seems fair enough to me.
Biggest drawback I can think of is people who allow tyre depot to tighten their wheel nuts with the air wrenches,,DONT let them do it,Insist on a proper torque wrench setting.