Worth noting most of the time the Corals sit idle in many setups, as Frigate only wakes them up if it detects motion with simpler algorithms on the CPU first. You gain capacity for a further 100 detections/sec for every Coral you add essentially. The corals are not sitting watching every single frame from every camera, which I think is a common misconception about Frigate.
It's worthwhile to spend some time with the docs - the mistake I always see made is folks passing a full fat 4k stream for detection at some silly FPS, which generally doesn't make the detection work any better and greatly increases processing costs.
If your six cameras really are generating enough events (100 a second) to saturate a coral, I'd be looking at what else I screwed up!
> https://docs.frigate.video/frigate/camera_setup/#choosing-a-...
Wireless cameras can also cause their own set of issues, but I can understand using them if you have to.