Migrating from rPi ZHA HUSBZB-1 to Yellow ZHA

I have recently received my Yellow, have it ready to migrate from my existing rPI HA install with more than 50 perfectly functioning Zigbee dimmers (GE). So most are routers. I’ve already done a dummy migration to the point that my old system has been recovered to the Yellow. But on this dry run attempt the existing zigbee devices all appeared offline.

So my question is: Is the migration from the HUSBZB-1/ZHA on my old system to the new Yellow’s coordinator via ZHA supposed to work. Do I need to do anything other than just a full system restore to the Yellow?

I want to roll forward to the new Yellow in a non-destructive manner wrt my old system and zigbee net for obvious reasons.

Any guidance would be greatly appreciated.

Thanks,

Rich