It's a PIA for logging into things (e.g.: companies who use three different redirects to three different sub-domains) but that complaint is my fault, based on how I've configured it.
That plus deleting history on close of Firefox isn't enough to thwart the most egregious adversary (e.g.: those with three-lettered names) but should be enough for privacy concerns.
For 2, I might also recommend Canvas Fingerprint Detector[1]. Instead of not replying (which could be, in and of itself, a fingerprint[2]), it generates a random fingerprint signature in response; though, in principle, this might be a tracking vector, as well.
[0] - https://addons.mozilla.org/sv-SE/firefox/addon/temporary-con...
[1] - https://addons.mozilla.org/sv-SE/firefox/addon/canvas-finger...
[2] - https://multilogin.com/how-canvas-fingerprint-blockers-make-...