Hmmm - Maybe not - As, of course, the older SAKs with bails had Celidor scales - Although those ones would be of the solid variety
However the modern ones are still solid at the attachment points.
I'd give it a go - Peening always involves very gentle (and patient !) tapping with the hammer - So it should be ok
Although, as you say, with metal or Micarta scales there would be no worry at all