But I could have been completely wrong. Anyone have real world experience?
(BTW - My site is small and 99% of users are not logged in, and 99% of pages are unchanging, so a perfect use case for a static site.)
Some perf tweaks I made were to point the main site’s wp-content/uploads at the WP htdocs via a nginx path mapping, and to tell SS to never export anything in uploads. Reduces the site generation to just the html, css, and JS.
The other caution is that it doesn't export anything that's not linked. So if you've got no links to the yearly archives, then you get no index.html files for /YYYY/ either. Unfortunately, the Archives block in Wordpress doesn't offer a toggle between months and years, so you can't just create another block in the "archive finder" page and set it to years.
The support forum section of wordpress.org for the plugin appears to be a lot of people asking for support and no comments by the plugin author. If it works for you, then that's probably not an issue.
My homepage running on vanilla Wordpress: https://www.skyfaller.space/
The same site using Simply Static: https://static.skyfaller.space/
Does it feel slightly faster?
[0] https://pagespeed.web.dev/report?url=https%3A%2F%2Fwww.skyfa...
[1] https://pagespeed.web.dev/report?url=https%3A%2F%2Fstatic.sk...