I enquired of MWS as to the recommended method for weight attachment. Didn’t really get a definitive answer other than knock ons might be a little better technically but if a customer wants stick ons, then that’s what they are given!
So at the end of the day, the proof will be in the performance when driving. My experience over the years is that imbalance often seems to show up at around 60mph.
And, maybe in my opinion, the wider the tyre the more critical the position of stick ons might be? Dunno really!