We need to able to warn when retriggering jobs on a platform with limited capacity. Basically, pick one of the platforms we have and mark it as "limited capacity" or something like that.
That way, when Perf sheriffs see new alert originating from that platform, they'll know to be more cautious when retriggering/backfilling.
For example, we recently added Raptor tests on the Android platforms. The tests run on about 20 devices. Doing many retriggers & backfills can block the entire work queues in less than 1 minute.