I just installed it 1 min ago and I've just tried to freeze and unfreeze one tab, so I don't know how/if it works in the long term. But it seems to be good for now.

My one problem with it is that I wish it had a visual effect on the tabs that you freeze so that you know which tabs are or aren't. Like a blue border around the tab would be nice.

Also I don't really understand why it's referred to as "Discarding" tabs, I think freezing or suspending is more accurate, discarding would imply completely getting rid of the tab...

What's missing is the ability to discard an open tab. For example discard the current tab and open the last used one

Sometimes when discarding Youtube tabs the other already open tabs from any website become blank and they stay blank even if i reload the page(F5 or CTRL + F5), only fix seems to be restarting Firefox.

Awesome, works as intended. If there are "Discard other tabs", "Discard tabs to the right" and "to the left" then it would be perfect.