Hi Jonathan,
I am not sure whether you are asking about out-thrust or down-thrust ... which is it?
On the subject of out-thrust, because the RPM does not vary much, many flyers have reported none or minimal ill effects from excess out-thrust.
As for the downthrust and or positive stab incidence that some find useful ... there is no clear concensus as to what is needed with a reverse rotation prop.
Regards,
Dean P.