Agree with the pro nerd then, on the 9. The square shape feels like it kinda blocks some stuff (obviously this is super subtle, and really just more of an excuse for me than anything else).
As to wheel weights, I don’t think there is a wide variance in weight based off of shape. Or that I want to forgo skating wheels or anything, more that it is a piece of information that is not listed is all. When EE3 came out and we all upgraded to 60s overnight, I recall thinking my shit weighed a lot more. Wasn’t necessarily bad, just heavier.
I did have one of my all time best days riding a skateboard, 20 ish years ago, on a setup that had these really fucked up spitfire cored wheels that were noticeably lighter. Shit was poppin. Wheels were terrible tho. Lasted a week and felt gross. 10/10 would.