This really is very interesting.
I went and looked again at that patent and at the patents that appear to have been stacked on top of it more recently.
The 2020 patent was abandoned. 2016, 2014, 2011 and 2010 patents are now showing and adjusted expiration date of June, 2026.
A far-optical device comprising a reversal system and an adjustable optical magnification means with more than fourfold magnification, wherein the far-optical device has an optical beam deflection means which at all magnifications ensures a subjective field of view of the far-optical device of...
patents.google.com
It looks like after June, 2026, barring any other changes, the FOV limitation will be no more.
ILya