Although, as they say, "the absence of evidence isn't evidence of absence", there is very little evidence of functional devices, rather than jewels or ritual/novelties. These items would not be described as marvels by Pliny or Seneca if they were artisan
tools. The Plantzos article "focuses" on whether the artifacts were intended as any sort of optical aid, not whether they were deployed as
tools.
Such lenses would have to be an improvement over myopic human vision. Consider the engineering of modern loupes and similar close up devices and the difficulties most of us experience handling a traditional magnifying
glass and a coin simultaneously. Now add engraving
tools to the mix. Look at existing
Roman glass pieces and consider if they could get optical
quality better than a skilled artisan holding something close. And consider all the really third-rate dies that seem to have been produced if auch devices were
standard tools.
I am not saying "impossible", but my late collecting friend Jay Galst was an opthamologist and he thought myopic engravers were a better fit for the circumstances. Such artisans could start
work in early teens at peak vision and have a 30 year career and
still be dead based on life expectancy by the age at which us modern folks start looking for reading glasses.