That's a common problem with filament printers.
One thing that yields sharp edges is laser cutting.
You could draw the parts in 2D, put a non-cutting mark where the edges of the film would normally lie and have the openings cut to the film image size. Have it cut from ABS, file the edges to make a bezel all the way down the window all the way to the non-cutting line, glue it all with ABS glue from the hardware store... a bit more work in a way but potentially more precise at the same time.