We manage to keep on top of the Peak District cave registry, more or less, and in many ways it's quite fancy now, with 3D models of many caves and systems, as well as surveys, rigging topos, photos and references. As volunteers we can only do so much, but it's been designed to be easily expandable, and our output should (hopefully) prove to be relatively straightforward to re-map to a book format when the time is right.
But I would rather keep the local registries local, rather than part of a larger national registry, if only as we're more likely to know what's going on in our area. That said, I bet many of us have only been to half the sites in our registry - there are so many!
https://peakdistrictcaving.info/