Tested on M1 Max: Floyd-Steinberg halftone + BLE pacing + a vendor-specific density command `1D 49 F0 nn` to print sharp photos on the Sugar YMP-01 thermal mini printer from Python.
Tested on M1 Max: switching a Python BLE client to RFCOMM (SPP Ch.2) cuts transfer from ~60s to 5.38s for a 140KB JPEG. Covers PyObjC quirks, macOS Bluetooth entitlement, and an isolation experiment confirming olie.xdev's 'possibly not required' steps.
