ST Link V2 Keeps last bin File open

I'm trying to figure out a way around this: After I program a micro, the ST Link V2 Utility keeps that .bin open as a default tab. So, on the next unit, unless you pull down the tab and browse to your new firmware, it keeps the .bin it just used, and programs the micro with the old firmware. 

The problem is that we need to put a differently encrypted file to each unit in production. It's a very time-consuming pain to track down a couple mis-serialized units. 

So: Is there a way to turn off that default tab? It even stays there after closing and reopening the program. If the person who is programming clicks on Open... for each unit, then they will have to choose the firmware. That was the workaround, but it seems human nature will always get in the way and try to find the shortcut when programming 10k units. They probably figure they can just skip to Connect and Program & Verify. We'd like to take that out of the equation for failure if possible.

(We're working on an executable that will automate all this stuff, but the contract manufacturers are still cranking through thousands of units, and we need to solve this now.)