Add log lines when recompute server is using cached data

[Jacek-ghub]

I think that recompute server is caching the latest recompute results. Would it be possible to add a log line when those results are being used?

I assume that for a normal operation, those cached results are used rarely. However, if there are plot duplicates across harvesters that connect to the same recompute server, those log lines would provide a hint that potentially there are dups in the farm.

I am not looking for a full info (e.g., plot / harvester names), but rather any hint that would help if everything else fails.

UPDATE:
Actually, if there are duplicate plots across harvesters, does the farmer checks for duplicate proofs before submitting them to the pool, or rather duplicates will be sent?