allow disabling of "preemptive blind retransmissions"
OsmoPCU already starts to re-transmit downlink blocks before the MS has had a chance to receive them and/or send the related acknowledgement in uplink.
While this is possible as per spec, and it is not a performance degradation as long as we have nothing else to send in downlink, it can be quite confusing when analyzing traces. In traces, one is primarily interested in actual protocol-level re-transmissions and not in the "preemptive blind retransmissions" that OsmoPCU generates.
So it would be good to be able to make this feature optional. This way one could disable those retransmissions, and all retransmissions observed in protocol traces would be (only) those triggered by the RLC/MAC protocol.