This worked PERFECTLY to remove the loading="lazy" on the featured image which causes the Google page speed test to complain.
It would be nice if the "settings" were a little clearer instead of in the Media Settings. I actually removed the plugin twice thinking it didn't work before I noticed the documentation mentioned where the settings for it exist.
Being a passionate minimalist, I recently found and used the plugin "No BS Image Slider" on a client site. But often only the first image would load, not the others. This seemed to be caused by WordPress lazy loading - the images scroll in on a pure CSS animation, and it seems like the WP JS for lazy loading evaluates all but the first slide as not visible - although they soon are. Empty space slides in...
I did not want to to kill lazy loading in general, and this was the only plugin I found which offered to suppress it on certain media files. I was a bit hesitant due to the previous bad review, but found no alternative plugin-based solution.
So I tried it - and it works fine. My slider pics are now not lazy loaded. The blanket option to completely suppress lazy loading works too, I tried it.
Finally, I had a look at the code: Nice modern OO code, nice and lean, no bloat (but does use vendor/composer). Code looked clean to me.