Roud now works on the basis of what singers sang rather than what folk songs they sang, so now former pop songs, Victorian tear-jerkers, music-hall pieces.... etc., are being given Roud numbers
The llogic of this, of course, is that it will have to include C&W - I knew severl traditional singers who sang, 'Your Cheatin' Heart' (as I'm sure, you did Nick
The index remains invaluable as a research tool for finding printed sources and for linking up variants of songs but, as far as I am concerned, it is no longer a source of reliability for distinguishing between folk songs (which were included) and non folk songs (which were not)
A sad loss to our understanding of folk song, I sorry to say
Manty folk songs eneded up on broadsises and some originated there, but despite claims, nobody knows which and how many

"Jim, how do you break a gold ring in two?"
The songs were based on the practice of lover's exchanging 'Gimmel Rings' which were made in two (sometimes three) parts which were separated when parting, each lover retaining a half - and joined together again when they united
Chambers's 'Book of Days' has a remarkable essay on them, v complete with illustrations
Some were beautifully made and expensive, but the cheap ones were riveted together and were deliberately scratched in a certain place by the lovers so they corresponded when they were rejoined - they were sold widely at the Country Fairs.
Jim