As you have observed, BLE does not have a very high transfer speed. You may have some minimal gains by setting the MTU to a multiple of 23. Either 69 or 92 would be the closest to 90. BLE is capable of full printing jobs, but it is not the fastest way with limit of only a few kB/sec depending on the device. For faster printing I would suggest bluetooth classic, or printing over a network connection.
Software Engineer Kutir Mobility
Posted on behalf of Zebra Technologies