Has anyone figured out how to automatically omit the "%QN" quantity if there's only one hole feature?
%QN is Smart Quantity. Like Smart Depth.
Go to the Smart Depth tab and place your codes there. Not the %QN.
Like %QC X for example.
Then in the Feature Callout fields use the %QN.
You may also find that legacy drawings do not work unless you thououghly recompute the views with Ctrl+Shift+Update All Views.
You don't mention whether you use the callout function on the dimension ribbon. Often this adds the appropriate additional info to a hole feature. And you can always add the quantity code, etc. to your dimension styles.
Before and after shown: