As far as I know the Forerunner 955 with Firmware 11.12 should be fully compatible with HRM-Pro and Firmware 8.8, but after updating the HRM-Pro from 7.x the watch asked me if I also wanted to connect an FP device. I declined that.
If I understand the last paragraph correctly, it should not show up as a Foot Pod.
Is that a bug and I can safely decline to connect the Foot Pod?