Cool. Thanks for the reply. My normal scheduled check reported a a few errors after I think a runaway Docker container made my cache drive unmountable. Managed to fix that and ran a check with corrections on that then reported zero errors, so I think all of the errors would have been overwritten as I was shuffling things around.
I searched and didn't find anything on the forums and didn't see anything on the Parity page in the Docs. Apologies if this has already been answered. Does a parity check with "Write corrections to parity" turned on report how many errors were found?