@johnlagasse ,
What it sounds/looks like is happening is that you are changing the Resolution of the Geomap Image.
See my attached video. When I create the image, the Resolution defaults to "Optimal" and the text appears all at a predetermined size, no matter my view. Then, when I change the Resolution to "Fine" we can see all of the text change to a new (smaller) size, even at my same zoom level. I then run the GEOMAPIMAGEUPDATE command with the "Reload Only" option, which does NOT change my Resolution, it merely reloads the image data. However, when I run the same command and select the "Optimize & Reload" option, the image then reverts BACK to the Optimal resolution, and we can see the text size change back to its original (larger) size (the 'Optimal' resolution size).
I hope this helps clear things up and identify your issue of seeing different text sizes.
Best,
~DD