Activating discovery renders an assorted variety of phones and gadgets since I live in an apartmentbuilding, so that’s really not an alternative having it on by default…
And afaik the discovery component won’t let me disallow any new bt-devices if present?
What is the specific error? Per the docs you don’t need to put anything in the service data field so there shouldn’t be any json errors from bad input.
Are you on a ‘public’ network for your whole appt. building? I don’t think discovery should be finding devices outside your private network.
If its only one type of device discovery is finding you can try ignoring it.
Do you have a blue tooth device tracker component loaded? If so look at the component page for the specific one you are using and setup track_new_devices