Not sure this pertains to the roller guard design- but anytime I replaced my stock factory slide with a alpine "slide guide" or a sunders "fast slide"
I could notice a smoother draw.
Problem was the Saunders would pull my cable over too far and the slide glide would eventually stretch out. So I forced to go back to the factory slide.

Somebody mentioned HCA was selling their roller guards for other bows; I searched their website but didn't see any for sell.

If they were it would be interesting to add one to my current bows. I bet it would draw smoother with a roller than string on plastic friction.