I rate all my films at half box speed than develop in Microdol-X 1:3, time is reduced by 15%. Gives very nice tonality I find. Not got any TMAX examples done this way but have a 100ft of TMAX 100 in the fridge so will be trying it fairly soon. This is how it works with FP4+, rated at 64, scanned on my Plustek 7600i. I find denser negatives scan best, and most of my best scans have been with negatives that would probably be too dense for printing well, so I also say err on the side of overexposure than under.