The JSON thing they have fixed - I think I didn't make it explicitly clear in my comment. But it was that tree view for quite some time after the new devtools r

The JSON thing they have fixed - I think I didn't make it explicitly clear in my comment. But it was that tree view for quite some time after the new devtools revamp. About the full browser hangs - maybe it was my own system, but I usually had Slack and Gmail open. And those tabs already ate a lot of RAM, making FF sluggish. Opening the scripting tab on my own dev site used to make the browser just get stuck. Devtools didn't use to respond either, but clicking on the close button sometimes worked, so I had to hope that I could click on the cross button without triggering the dreaded "This app has stopped responding" dialog.