Delete some SMS transports from the database:
delete from message_transports where message_transport_type='sms' and letter_code != 'HOLD';
Check patron messaging prefs in OPAC: Only the hold notice SMS has a checkbox.
Check patron messaging prefs in the staff client: Every SMS transport has a checkbox.
Should only show the checkboxes for existing transports.
I haven't tested, but the same may happen for the other transports too.
Already fixed in master.