In principle, I'm sure you're right, though I know nothing of
spintria and the literature. Epigraphers that I have known have relied on it, that when, for example, an
inscription was set up at the entrance to a sanctuary saying something about profane practices, such as burials within the temenos, it is the best conceivable evidence for such practices having occurred, and frequently enough to justify setting up the
inscription. I remember a little Middle
Byzantine church in
Athens which, 50 years ago, was crowded round by later houses and garden walls. On the back of its little apse was painted, "Outhouse use of this place forbidden!" Well, it actually said
Apagorevetai to kropeîn, in case you know Greek. Today, of course, like the rest of the Plaka, it's clean and tidy enough for Disneyland.
Pat L.