In RMS 14.1, order search by order number (FM_ORDHEAD) seems slow

We are doing some performance testing, and looking for tuning opportunities.  We are using a load program, and scripting access, to see what kind of load and response are encountered.

When doing the order lookup by order number, we noticed an odd behavior - the average response, for a single user, to access the screen if we select an order with a large number of items, is around 30 seconds.  The following test results are excerpted from our analysis.  Does it make sense that the same queries would be executed 2+ MILLION times in this scenario?  Is this just the cost of doing business, and looking up orders with a large number of rows, or are there areas we should look at to improve the response, here?