Thanks for the reply Surgeryhead, much appreciated!
I purchased the main sourcebook from here on itch, as I wasn't sure which was the "right" source, although it seemed similar to the one on EF (24 pages, the 3 random tables, etc.).
As far as the download mentioned, I was referring to the "SQUISHY PRINT 12-29-23.pdf 92 MB" file on this page ("Update to Combat Rules"). It seems to be a file that was available for download at some point, and the size made me think it was different from the main sourcebook. I of course could be wrong about this, so apologies if so.
Thanks again for taking the time to respond to these questions!