Shhhhhh! You might screw up sales for all those folks hawking those "racing" pumps and plates. I'm sure you wouldn't want to be responsible for companies like Fueling losing sales and money. 
Assuming a stock pump that isn't damaged or worn, there should be no oil pressure issues. Most of the low pressure at idle concerns can be traced back to the lousy bypass valve and seat (heaven forbid Harley ever fix their poor quality). There should be NO oil bypassed at idle, and yet many do in fact bypass. I'm guessing a person could fix a leaking bypass for one heck of a lot less cash than buying any of those aftermarket "racing" products.
JMHO - Jerry
I have a question about this. Let's say a 06 touring model comes in with low oil pressure. I get a ground plunger, I test and set your pressure with my test gauge by stretching that spring or shimming. I even lap the seat. I put it all back together and put the bike through cold and fully warmed up test.
A couple different results after the 4-5 hours of labor I just spent. Stock Y-pipes can be a mother.
1. No impact and no effect. No change in pressure at all.
2. Pressure raised a bit but after putting 5000 miles on the pressure dropped because the spring lost the stretch I put in it.
Have I just married myself to your problem? I'm I responsible for the problem after it popped back up? Do you think that customer should be pushed to the front of the line? I'm I out of line to still want to get paid for the time I spent? Even though the end result is it didn't fix your problem? Sometimes a sale is made not only because it is a better part, but in the long run. It can be cheaper to spend the money now on a part than to pay me for doing the job twice and loosing out on the riding time.
I'm asking this not to argue. I really would like feedback. There is no training for this. This isn't covered in a Bradshaw book. When things like this do pop up. I talk to different shops and get input, but the final call is always a tough one. The best transaction are always the ones where both parties feel like they got a fair deal.
I understand that there are crooked shops that will try and milk every last nickel. I also understand that there are crooked customers that always try and get something for nothing.