Yes, I had considered that. In typical fashion, I spent an hour or two trying to get it to work with no success, then as soon as you suggested it, I tried the same thing again and it worked! It's sufficient; since it's an intro, I won't need to worry about page numbers changing as I continue work (like pagination).
A couple questions:
I actually thought the --- \cat toc\cat* --- information in the repository might be a mistake until I saw your example here. Is that needed one time, and then after that it's not needed?
Is it possible to turn \ztocbefore off? For example, if I'm printing an OT ToC and then a NT one, can I have the intros before the OT toc but not before the NT one?