I received a reply from the 'teacher' in the video I'm using and he explained enough so that I was able to essentially reproduce what he is doing.
The solution to Tape remembering seems to rely on clicking to set the destination of the guide, then key-in the precision distance you're wanting.
Activate Tape, Click on a reference (guide or axes or object), drag out, click again, . . . THEN key-in the desired position of the guide if I want it to hold on to that for other guide placements. Tape: click, drag out, click, key-in 1.5". Guide is set regardless of where your second click lands.
If you lay down a subsequent guide and key-in say 4.5″, it will place it at the 4.5″, but won’t remember it. Tape still has 1.5″ locked in its register(?). You have to key-in the 1.5" (or whatever distance) AFTERyou click the 2nd end point.
cotty's screencast is showing this, but is difficult to catch unless you know what to expect; happens right after cotty clicks to set the first guide; keys-in "1" to re-set the first guide back to 1mm(?); from then on Tape has the "1" in its register.
The 2nd thing I learned through this is: I did not know you could key-in the precision dimension AFTERyou place the second click or destination point. Tried it with Move also. As long as the item is selected you can continue to key-in alternate destination points until you’re satisfied with the location or fix your mistype, perhaps. Very cool!!
Yep, I'm a newbie so the 2nd thing may be something everyone else already knows, but it is key to having Tape recall a key-in.
Thanks for your help.