I needed a LTE-A router and found this model having a Cat 18 LTE modem at an excellent price point. I was missing VPN functionality in the OEM firmware so I thought it would be great if it could run OpenWRT.
Huge thanks to @bmork for all his work, especially around NR7101 which is very similar to this device.
I've been running OpenWRT for a week now and haven't noticed any issues so far. I cannot really compare it to OEM firmware as I didn't have it running for more than a couple of hours after I unboxed it 
I hope the PR gets reviewed in the near future.