I don't have a solution, just observations;
I Took a look at the callout (hole dimension text) noting that there were the following; <NUM_INST> <MOD_DIAM> <hw-diam> <HOLE-DEPTH> and <hw-depth> variables.
My guess is that without sharing these, any other like-feature would not dynamically change/update the quantity variable. This is true even if the holes have the same dia./depth dims. but were created separate from the initial hole feature (or holes if that's the case), i.e. .....Hole1, ......Hole2, etc.
Now I detect from your message that you already know this;
If I want my text to update with the proper qty. I would insist the hole feature itself be editted, adding or subtracting holes or points as needed. I've done this easily and even placed holes with the hole wizard, on perpendicular surfaces (think a block of Swiss cheese) within the same command.
Text callout updates qty's. accordingly with no problem but one major caveat; since most views are shown planar, it is poor practice to show a qty. of features greater than those shown in that view; hence it makes sense to create hole features unique to the plane they are being placed on, the qty. also unique to that grouping.
Most of us work in multi-user environments so it would not be a bad idea to make it part of the design guidelines that such features be editted within the command (if on the same plane and of same characteristics) in order for drafting notes to update properly.