Question Changing app display size?

I have sideloaded a couple of apks to the FireTV for sports. I'm using the WatchESPN app from the Amazon store and that works good. I have side-loaded the PAC-12 NOW app and it loads up fine on the FireTV, but the edges of the screen are cut off in this app only. Is there a way to force the app to run at a certain display resolution to fix this issue? Any suggestions appreciated. I am also working to get the Watch NFL Network tablet app working, but it requires Google Play Services, so I will have to side-load the Play Store first.