Yeah it's not super easy, that's why professional alignment equipment uses a rack. But it can be done, I've done it more than a few times before I went to adjustable UCA's.
The Hunter turn plates are a few inches tall, I use them with a set of low profile race ramps so I can drive onto them without messing up the ride height. I also have a set of slip plates for the rear tires that elevate them about the same as the front. But the SPC UCA's I have are much easier to reach than the actual camber bolts.
I actually have a pretty complete Snap-on alignment set up from the 70's, I'm still in the process of setting it all up and calibrating it. Because of my aluminum hubs and wheels though I'm pretty much stuck with using wheel clamps anyway, so honestly I don't think the Snap-On set up will be any better for caster/camber. The optical toe gauge should be better though.