Running two instances of Portable Apps at the same time

I have an old copy of Portable Apps Platform on thumb drive #1. I have a newer (17.1.1) on a second thumb drive. There is one old app on the original thumb drive that I really would like to run at the same time that I am running the rest of the apps from the newer drive.

Today I do this -- insert both thumb drives. Launch portable apps platform from drive #1 and start the old application. Use it to add data to a database. Exit the program, close portable apps platform (without ejecting the drive). Launch portable apps platform from drive #2. Use programs from this instance to perform other work. But if I need to do more data entry, I have to close all the apps and then close the portable apps platform. Start up the other copy of portable apps platform, etc.

What I'd like to do is to have both of instances of the portable apps platform active at the same time. I've configured one with a blue scheme and the other with an orange scheme (War Eagle!) so I can tell them apart.

My question is -- is this possible and safe? The data on these thumb drives is critical and I'm not willing to experiment and take the risk that I lose any of it. (And, yes, I back up these drives routinely, but I could lose a day or two of work if the drive should crash between backups.)