Issue #1 with the white box issue continued...
So I ported my "fix" over to a new project since I was seeing the same issue now that I have a Roku TV to test with. The fix of setting 0xFFFFFFFF to 0xFFFFFEFF (barely off white), worked on a few of the rectangles, except for the main view area.
After spending time trying to find a common reproducible situation, I change the opacity to see what might be happening behind the view and that change ended up being another fix.
So, I set the view's opacity to 0.999 and it fixed the white box issue ... again.
To sum up:
Project A was completely fixed by simply catching any Rectangle trying to use 0xFFFFFFFF as it's color.
Project B was fixed by using the fix for A as well as setting the opacity of any other rectangle with the problem to 0.999
I feel like I need to shower now.
At this point, there's definitely a bug in the Roku TV OS and how it handles rectangle's color/opacity. The only difference between the 2 apps is maybe the background color of the 1 scene. In "A", it's 0x000000FF (black) and in "B", it's 0x212121FF (dark gray). I've tried setting both scene backgrounds to black, but that didn't change the fact that I had to change the opacity in B for it to not show a huge white rectangle.
Still confused on what the real reproducible steps are, but maybe someone else has some insight as to why and how to work around it better than how I've described