Hmmm... that's not quite what I had in mind. I was thinking I could have it aligned for the street with no shims, and then have it aligned for the track with shims, keeping the arm lengths locked in. That way, it would be easy to duplicate the alignment specs multiple times from track-days to street-driving without needing to take it to someone who knows what they are doing on the alignment rack.
Assuming there are no major differences in length from one side to the other, would there be any problems doing it this way?
My dad owns some old alignment equipment (got it when he bought out another body-shop's frame equipment) but neither he nor I have ever used it.