[mdaniel]

"Blocking" is not the right verb, but this is representative of a whole category of bugs in dev-tools that makes using FF for dev work very frustrating: https://bugzilla.mozilla.org/show_bug.cgi?id=1553836 ( Cmd/Ctrl+A selects the entire panel content so it's hard to copy just a response payload for example), open for 7 months

I was tracking some similar ones related to displaying JSON in the Network pane that were open for years.

In my specific case, Chrome also displays EventSource events just like it does with Websocket frames, but Firefox treats that as a normal XHR, waiting until the very end to display the content. That is a little closer to "blocking" but also very niche, I guess