...and after that first pass of enabling only what's needed to get a site to work sufficiently well, that site tends to be significantly more pleasant to use in future.

I enabled JS for just eff.org, and coveryourtracks tells me I'm still spewing 17.12 bits of fingerprint all over the internet. I suppose it'd be possible for a browser to randomly rotate stuff like user-agent through multiple common values to mitigate that.