EpisparhThere is significant difference between can work and optimal. Your personal bias against small rocks may prevent you from finding good deposits - I've seen plenty of 40-60% small rocks both platinum and painite.
I should have clarified that more. I didn't ignore the small asteroids. When I go out mining, I launch a limpet at everything in sight to find something to mine. It's just been extremely rare that the small ones end up containing any recourses worth mining. Again, that could just be coincidental in my experience. Part of the reason I use the wing tip weapon mounts for laser mining is because the underbelly hardpoints have an abrasion blaster, sub-surface displacement missile, and seismic charge launcher. The ship is setup to be able to mine anything it may come across, while still having at least 2 large weapons to fend off AI pirates, and the projectile mining modules are easier to use when in the more center mounted slots. Lasers can just be held down and adjusted as needed.