Z-Wave Switches vs Contacts, and the database

Absolutely correct.
he formatting in the Item “label ” section has something of an oddball or magical power though, it gets used in non-sitemap ways as well.

Here’s an old, but useful discussion. In OH1 bindings, the author could provide features to “map” say a binary input to a Switch or Contact Item.
In OH2 things/channel world, this is no longer so easy.

I understand profiles should address this restriction. New for 2.4, I don’t know how extensive the implementation is yet.