OsmoBTS on RAD1

Hey OpenBSC, Tom, I've been working on getting OsmoBTS running on the recently open-sourced Range Networks RAD1 radio. The code is available here: https://github.com/kheimerl/vbts-openbts/tree/osmotrx. I am stuck now and I was hoping the mailing list might be able to provide some perspective. With the RAD1, the system is beaconing correctly. However, phones are unable to camp. I logged a phone trying to camp on both the RAD1 and a B100 to compare the output and see if anything jumps out. The osmoBTS/osmo-nitb logs are seemingly identical, but the transceiver outputs are different. Both of the transceiver outputs are attached. The only big difference I see is in the "underflows" on the RAD1, which in my experience is a deal-breaker; that's not usually an easy fix. Does anyone have a different perspective on what might be going on in here? Thanks!