This is a false equivalency like saying if you have observed one 1950s television program you do not need to see anything further from the concept of the television.

At best, your effective diameter via your concaved glass might be 10m. This is unlikely to be felt shaving and only slightly when honing.

Please reduce your diameter to 8m maximum, but at 5m to maximum 8m primary axis ( = maximum diameter upon terminus of cutting edge), the changes will be undeniable.

Below 5m diameter, the visual change in bevel width should begin to become apparent if one is only used to observing flat V-shaped bevels.

The best functionality will come from a small diameter (1-2m) to thin the rear or bevel width without addressing its apex, followed by successively larger diameter refinement/finishing to guarantee a precise terminus.

The concept of wheel shaped convex hones is much more complicated than saying "here is visual proof I have used one slightly dished sheet glass, so I therefore understand all manner of wheel-shaped abrasives on hollow ground knives, at any diameters".

When you significantly thin the entire bevel form and reduce its cutting edge as well, the difference in the manner of the shave is well established, as has been [in German-only text] since 1834.