The 'boldness' of a hotstamp is a function not only of the type font selected when the die is made but of the heat, pressure, and kind of foil used in the stamping process. My view of your scans would indicate the chip differences you show are due to one of the latter process variables, most likely the heat and pressure used in the stamping operation. If you have a hotter die and increase the pressure, the die penetrates deeper into the clay and results in markings that appear larger.

The problem with trying to designate these as chip varieties is that there is in general a continuous range of marking sizes, since the heat and pressure can be anything above that required to melt the chip and transfer the metal from the stamping foil. Thus you could find a very large number of 'sizes' and a very large number of varieties for each hot-stamped chip.

I hold to the idea that process variables don't create chip varieties. Tooling changes or color changes in the basic chip material, inserts, or in the artwork for the printed inlays are worth considering in designating a new variety for the collecting hobby. That said, Meyers, Knapp, and Wheeler are the ones that have to make the decision to list any new variety of any of the Nevada chips they catalog.