"The thing I tried to avoid was a moving tool. Solid tool, moving tire."
??? I don't understand that statement. I have a "track stick" similar to your toe-in jig left over from my stock car days. It has to be moved from the rear of the wheel to the front of the wheel, sometimes more than once to compare measurements. These plates are put in place and not moved until the job is finished. Yes, saw cuts can be used instead of a holesaw; just a matter of preference. The radius is cut out of the top to clear hubcaps, spokes, wheel weights, etc.and also reduces overall weight. If you put braces or props on these, they need to be adjustable; not all wheels are 90 degrees from the ground. Some street driven cars (especially those with beam or tube axles) have positive camber and many race cars have negative camber.