Yes, definitely. I once had a halo with micropave, and the diamonds were SO teeny tiny that they looked like dots. It's hard for a tiny melee diamond to sparkle much when it's such a small size. That's why some vendors use single cut melee. https://www.victorcanera.com/blog/single-cut-and-full-cut-melee-explained
Yes for two reasons.
1)the bigger the diamond the more sparkle it yields.
2)The area covered by the gold while setting the diamond is larger in % when the diamod is very small (less than 1 mm)