Eth pools reject NO shares, unless stale. Dupes they consider too compute-heavy to return negative responses for.
You mean that from miner's POV the hashrate will be higher, but from pool's POV, this will be kind of cheating?
From pool's POV, most will silently drop dupes. The ethminer tends to handle HW errors by not submitting at all - of course, this isn't important enough to tell you about it.