“…if your ROC drops to near zero in CLB or OP CLB, I'd think that may be nature's way of saying your speed (selected or managed) is a tad high….”
Yes, of course. Obviously speed would be reduced first to achieve the best ROC, that’s what I have always done.
“As for being concerned at the RoC varying with a few knots speed change, I've never understood why this is seen as a problem.”
Exactly, kind of what I am getting at. There is a lot less “shop” minding needed if you accept a variable ROC with a fixed speed. Distractions approaching top are generally something out of your control.