Hmm, I wrote that a long while back and (a) it’s poorly phrased and (b) the app has changed slightly since. I’ve now struck that sentence. It used to be that in the app or doc preferences you could set the defaults (for example in v5), but that is now gone. All new notes get the same width/height according to the default values for $Width and $Height. You can alter that on a per-TBX doc basis via the System tab of the Document Inspector. For that you need to select the desired attribute on that Inspector, e.g. $Width, and then alter the default to the desired value. That change affects only new notes made after the change.
IF you re-read the part of the article of prototypes (before the sentence quoted) it explains why width/height (and some other intrinsic attributes) don’t inherit.
Your second post shows you’ve found the correct method to use where you do want to set such attributes. You use action code in one of a number of settings: agent action, container $OnAdd action, rule, edict (possible but less likely), or a stamp.
Don’t forget a rule runs all the time but you probably want to set the width/height of the note only once (or occasionally reset/correct it if altered). Therefore you might like to consider a stamp.
[N.B. I’ve now corrected aTbRef6 to remove the now-confusing sentence. Sorry for confusion caused in the interim. The resource is now 12 years old and the app changes over time. I catch most things but miss the occasional one.]]