Quick follow up. I used
@David L 's guidance above to use RTMP feeds and saw 0 drops over the course of ~5 days on my POE doorbell.
Separately, I emailed Reolink CS and they sent me beta firmware to test out. After applying the beta firmware I was able to turn RTSP keep alives on and use the RTSP feed without any drops for ~1 day so far. With the beta firmware I was able to follow the guidance here to add the Doorbell via ONVIF:
How to Add Reolink Cameras to Blue Iris
The benefit here is I'm able to use ONVIF triggers, use the lower quality sub stream for triggers, and the full 4k stream for the recording and live view in BI.
CS said the firmware is beta but will be rolled into prod with the next release.