Can I put my "pixel-peeper" hat on please? Having a look at your images they all show pretty significant chromatic aberration. To see what I mean have a look at the large white lettering in the background. Near the edges of the frame there is a blue fringe and on the inboard sides of the letters there is a yellow fringe.
This is probably to be expected as the magnifying glass won't be colour corrected. I would be interested if you could post a couple of shots of a similar scene (with the white lettering like your first image
), the first of which taken with the magnifying glass in place and the second one taken without the magnifying glass but digitally zoomed in post-processing so that the same part of the scene fills the frame.
It may be that the magnifying glass is giving you real benefit but it would be nice to see an A/B comparison.
P.S. Hope you don't mind but I've moved this thread to the Macro forum as I think it fits there well and you might get some more feedback.