I put my pulleys on the other way, set screws out. This lets you get the belts as close to the motor mount as possible. The closer the belt the less of a moment arm, the tighter you can get the belt. I’ll try and get some pictures when I get home.
Also if you lengthen your belts just a bit when you use the zipties they can sit a bit more flush. if you get it right the eye of the belt will line up with the zip tie indent and the belt will sit right up against the corner block.