I think you underestimate Lilypond.
this is not true. I well know, and stated several times, that LilyPond has the power of a nuclear reactor.
And I'm sure too that with customizations you can do whatever you want in the cover/introductory pages.
What I meant is different. For these pages I don't want to add or expose logic. This is not how I intend typography for such pages.
The example Aaron showed already added *logic* to the template, and so your example does:
\on-the-fly #part-first-page \fromproperty #'header:copyright
(of course thanks again Aaron and you for your examples, which are precious: they clarify to me how LP works)
But, IMHO, such pages should not have logic, unless you don't have alternatives.
Normally, I would prefer another approach, which I consider *standard* for these things: have a set of templates, pick one of them and do NO customization at all, unless you don't have alternatives. Your example would fit my requirements if it was wrapped by a template, but it is currently not.
This is how you can have a *readable* code (don't misunderstand me: your code is excellent, what I mean is different). Of course I could wrap it, but for future different cases I would have to do the same procedure, which is tedious.
Hope that what I mean is clear, now. In any case, this discussion is interesting and I think it deserves further insights. Thanks for your contribution!