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The folks at Motorlola stated that my previous levels (+11 to +12.5) were higher than desirable. I haven't had any level warnings in my event log since, and no errors are showing yet after about 40 hours. This is not conclusive evidence, but it's looking good so far.
As long as your not going through any splitters or amps, a attenuator just makes your signal levels "prettier" not so much better. However your in spec either way.