I have a 66 Mustang with a pretty heavily modified front suspension including 72 spindles that have slightly different geometry. I have Baer in mine. This is a street car and I'm by no means an expert but I do my own all my own work including alignments. Bump steer is a big problem on these cars once you start doing just about anything. On the vintage board I hang out on the thoughts is, how much you will tolerate. It's one thing going into a turn at 30 MPH and another at 130 MPH.
I started building a bump steer gauge with electrical 1.5x1.5 unistrut with floor flanges and 2 HF dial indicators. I still need to find a suitable flat plate for the hub to measure off. But do to the lack of time and what everyone says in the vintage community, don't waste your time measuring, just slap all the spacers in because you're going to need them all. That's basically what I ended up doing. How I was testing what works was the crest in the road in front of my neighbor's house. The speed limit is 35. I just kept driving over it until there were no noticeable problems which ended up putting all the shims in. Not very scientific or professional but it drives fine.
What some of the guys do to check bumpsteer on the same forum is to park the car up close to the garage walk. Block the body at ride height, remove the wheel and spring and mount a laser level on the hub. With the hub at normal ride height, turn the laser on and the dot on the wall they draw a vertical line on the wall. Now they cycle the suspension up and down and adjust the bump steer to keep the laser dot close to the line on the wall. You also have to keep in mind is the camber curve but you get the idea.
End of the day you have to do what's practical and cost effective for you. On my alignments, I never did one before. My car drives great. I believe I have both sides within 1/8° as far as camber and caster is exactly the same. I would love to have a professional check it out just to see if I did as good as I think. But that would entail me spending money for something I already did, so it's not going to happen.
I cut it 3 times...and it's still too short!