I guess I’m old, but I wouldn’t call the foam rings or inner tubes a “boot”; donut sounds like a better term for those.
The TC “boots” we had on our truck back in the 1960’s and early 70’s were made of vinyl and custom made to fit the TC and truck. They required the entire removal of the TC window and truck window. The boot was screwed into the TC and fed into the cab of the truck where it snapped around the window opening. Of course, that was back when our TC windows were at least 2’ wide.
We do use a boot now, but the opening is only large enough for our 4 legged family members. When I use a foam insulator around the outside of the boot, I mask the areas where it contacts with blue painter’s tape.