It would be nice to have a 'Mark all as read' button on Hubski. A thread would go back to unread as soon as a comment is added.
There's a way to, somewhat crudely, emulate it with a 'save' option (it's under the post title). You'll get a notification every time there's a new reply anywhere in the comment tree. I think that what you ask for could be fully done with a browser extension (track what you opened, filter those where comment count hasn't changed since your last visit – nothing hard here), but that's a can of technical worms I'd rather avoid touching myself.
You can "dismiss all" from notifications. Just wondering -- are you looking for a function which would be, effectively, an "ignore post"/"ignore future comments" function? Seems to me that might be a little different from a true "mark all as read" -- mainly because it would be a proactive function not a reactive...
I'm going to try to explain it better! On this image : - The first post "LET'S GO SHOOT AN ASTEROID, Y'ALL" is not 'clicked' yet and it appears white. - The second post "Who Is Left on Hubski?" is 'clicked', and it appears greyish. I wanted to know if an extension that would mark all my feed as 'clicked'/greyish existed or is an option. Like this : https://chrome.google.com/webstore/detail/hacker-news-mark-all-read/fghfahcbhpdeeaaofcefaoodmfejieok but for Hubski :)