Can sites' "cookie controls" override one's overall browser settings?

[otherego]

I mentioned elsewhere that I'd had a look at the cookie controls offered by eBay through their cookie banner - the post is here:

https://community.ebay.co.uk/t5/Computing-Advice-Technology-Chat/eBay-and-others-are-their-cookie-po...

if anyone cares.

Like most people - presumably - I always block third party and persistent cookies across the board in Firefox's preference options. Never having messed around with the controls offered by individual sites before, I couldn't help wondering whether anything one sets there would override one's normal settings - or are these banners and the "controls" they link to  really superfluous for folk who already prefer to control what cookies etc are allowed to be set through their browser settings?

I can't think of any way this could happen in reality, but I really don't know for sure. I found no cookies on the machine after playing with the banner and its links. Ironically, banning anything other than session cookies probably makes those settings irrelevant on subsequent site visits, anyway.

But I wouldn't mind a little reassurance that my Firefox settings can't be altered on a site-by-site basis by the sites concerned.

[*scyllabub*]

I was reading this yesterday, OE, and it made me tired (it doesn't take much).

What I plan to do, when I get around to it, is pose the question on the Mozilla support forums - because I would like to know the answer