The most encompassing answer I can give (That is site software specific) is that whatever settings need to be turned on on day 1 upon joining,
If they don’t effect site functionality, or my enjoyment of the site, I never look at them a second time.
I don’t bother with custom settings,
I don’t bother with the deeper capabilities of any site
Mostly just read and use simple searches.
I have 3 phones, 3 tablets, two pc’s, 2 Mac’s, all in rotation.
Because of auto updates, I chase settings and passwords all the time. I’m sick of it actually.
I don’t worry about settings that don’t seem to hinder reading and searching.
