If the extra weight (if any) is all at the rim then maybe worth a mention, I suspect any weight difference is at the hub which may affect the un-sprung weight but not that the average rider would notice.
If we are going to get al techy about rotational forces, un-sprung weight, rolling mass, gyroscopic effect etc. then we need to ditch the big chunky tyres for a start. That's where the foreseen problem would lie if any.
Just remember a few years ago the big players changed to 16" rims for better directional changes, they weren't long changing their minds back to 17" as the bikes became too twitchy and unstable.
I say be carefully what you wish for, as you get nowt for nowt.
The nice thing about spoke wheels is if you ride off road you can bend them and still get home on a square wheel. Repair is easier too. There is a reason dirt bikes don't run cast wheels. The tube tubeless debate is another story both can be repaired on the road. I read somewhere there is a product you can use on your rim to run tubeless tires on a wire wheel . you may want to check it out. But If you are that concerned about a few pounds on a scrambler maybe your should buy something else or go to the gym.
