I fixed it! Yeah!
It took a *bunch* of googling to track down what to do. I had to download a dell update to give me an AMD Radeon controller. And the thing was completely unintuitive. But I got through it. I found the "graphic switcher" section, and then the add installed profile section and then the browse button and then added open rails to the list of programs and gave them a "maximize performance" setting. And rebooted.
FPS of 63-68 now on the testing build!
Now - do I go to bed, or do "further testing . . . " ?
Thank you to everyone for your help!