Supporting 911 calls with the bare 911 number is not the same as overriding the phone's default 911 handling and I doubt the FCC has any regulation that says a

Supporting 911 calls with the bare 911 number is not the same as overriding the phone's default 911 handling and I doubt the FCC has any regulation that says a provider functioning as a third party on a phone is required to _replace_ & disable a working built in emergency dialing function with a broken app function.