Wider rims are a real good idea no matter what.
Even if they were not lighter, tyres fit better and bike WILL handle better which is more of a safety upgrade
Yamaha have made some real dogs, much worse than almost ANY Honda (excepting the VF range, including gear driven cam models)
At one time they also couldn't make a wiring harness that lasted long enough to survive trip from Japan (un-crate, order new harness, wait couple of weeks, test harness, order new harness, await, test harness -yay, at last) Suzuki were bad but even ANY LUCAS harness was superior to early ~ mid 1980's Yamaha
I remember many Yamaha owners who actually believe the RTS was accurate (race tuned speedometer - much cheaper to make a fast speedo than a fast bike)
I've also re-built more Yamaha crankshafts than Honda, probably in the order of 100:1 (maybe more, never kept count)
Yamaha two strokes are not the be all and end all, they are fast and fragile, all the air cooled ones teach you to keep two fingers on clutch lever at all times waiting for the seizure
For racing, two stroke was mandatory, on the street, doesn't really matter, even a full works GP cheater 'GT750' motor would get blown away by a modern 600
Oh, the other issues I've always had with Yamaha, first year models cannot keep second gear in the transmission (at least not without losing teeth or dogs)
and, even after 30+ yrs, they still ship brand new bikes weeks or months before shipping even basic service items (oil filters, air filters, clutch cables, brake pads)