Do you use Bluetooth LE? This could certainly improve https://code.briarproject.org/akwizgran/briar/issues/44, especially when you can disable other connection methods (https://code.briarproject.org/akwizgran/briar/issues/978).

BTW I saw https://code.briarproject.org/akwizgran/briar/issues/303, but this is only about discovery. It would be better to always use the LE mode, if both contacts/devices support it.