I had ss 1.75" risers, and later .75" risers (the same ones cut in half)combined with Heli-bars.
I never had an issue, probably 15k miles before I switched to Spiegler topclamp and dirtbike bars.
I see the concern with risers, but risk is minimal. To each their own.
I personally wouldn't say the risers are bad idea. I would only use solid material instead of washers. To make a more structurally secure and stronger part.
With the full plate spacer, it's no different than without it (other than improved comfort). The top plate the bars mount to is the same, only taller. The bars are still in the same spot (just higher), supported the same underneathe.
With bar stock spacers, you lose some of the strength of the perimeter of the top plate contacting the upper tripple clamp.
That is a thin edge only, roughly an 1/8", but it still helps.
Real problem is that the top plate is cast aluminum. So it'll break, not bend.
In the many miles of using spacers on my gen2, I was fortunate enough to never have a problem. Including several potholes, a few hard landed wheelies, and one damp fork at 15 or 16k or so, and I replaced fork seals.
The top clamp held up.