I’ve completed the capture I’ve mentioned in various other threads about a 1 year course I took, and tested it in Google Chrome. It works. Along the way I saved various .wacz’s. The most recent one is about 5 GBs. Prior to that I had a 1 GB (lots of multimedia added since then). The 1 GB works. The 5 GB lists zero URLs in https://replayweb.page/. So as far as I can tell there is no way to access the month or so of capturing I did when going back to .wacz. I do see all the data, and can access it in the Chrome extension, but would much prefer it backed up, and saved to .wacz.
Any reason I see no URLs in the larger .wacz? But the older, smaller, .wacz works just fine.