Yesterday I was at a customer’s office and he expressed frustration on how long it took him to set a biditem price to a maximum percentage of the estimate. His problem was the calculation had to exclude the mobilization  item (the % item) itself. So the calculation is as follows
(Total Bid Price – % Biditem Price)/Total Bid Price x 100  ≤ 4%
As a default HeavyBid does not subtract out the % biditem in the calculation but you can change the default to do this. It is TOOLS>PREFERENCES>BID SUMMARY/PRICING

If this is the common for all or most of the entities that you quote set this default in the Master estimate.