I've accumulated a fair amount of rep on one site and don't want to lose that across the network, but also do not really wish to be re-engaged in that site. I was wondering if there was a way to simply disable site-specific notifications from specific sites (up in the notifications area). If not, would this be a valid feature request?
This is probably not the answer you were looking for, but if you're desperate it'll do. I wrote css for the stylish addon (chrome or firefox) that hides notification links to a particular stackexchange. https://userstyles.org/styles/110509/stack-exchange-notification-hider In my css you'll have to swap out toxic.stackexchange.com for whichever SE you're trying to ignore.