the Delta 1 Bes-Align assumes the rear mounting flange is exactly aligned with the lens axis, the Versalab Parallel assumes the front flange is exactly aligned. Maybe, maybe not. It is still best to check on the easel with a micro-sight and test negative.
"As far as the column is concerned I would have to check to see how much that varies. "
moving the head up & down to change enlargement AND refocusing the lens for different distance will need to be checked for each enlarger and lens.
if you need to be that accurate, you need to be THAT accurate, should only be needed for big (20 - 30X) enlargements.