If you're sending back conversions to an offer (or lander) and need to work on a revshare basis, you can handle this via an extra parameter in your postback.
Simple add rev_share=50 to your postback and it will automatically adjust the value of rev passed by the rev_share value in percent.
So passing rev_share=70 and rev=25 will result in a revenue value of $17.5 being used for the conversion.
Allowed values are 0-100, values outside of that or non-integer will result in the parameter being ignored.
There's no need to change config at the offer level in FunnelFlux -- this can be adjusted simply via the posbacks.