Randall....I can't honestly tell you the answer to your questions, as I am using a new scanner, and this whole process is new to me.
I can tell you that I am scanning 120 black and white negatives from the Honolulu round house (1956) in black and white and converting them to positives, and I can count detail on my 17" computer screen that are about two mm apart. The color Hasselblad stuff I am scanning right now looks great, and I am delighted.
Of course I don't feel the need for ultra high scans because I have no intention of tempting a low-life, to try to take my copyrighted images to press. I am confident that the images I will present will be more than entertaining and educational for the majority of the audience.
Thanks for your interest. Be well, "Bo"