When I'm working with devtools -> network, I'm adding some domain filters there. How I can preserve that filters when close and reopen devtools? I'd like to not enter them every time I'm opening devtools -> network.
The simple but unfortunate answer is that the DevTools do not preserve any filters when closing them. And there is currently (as of Firefox 85) no option that controls that.
I assume one reason for that is to keep the memory footprint of the DevTools as small as possible when they are not required.
Having said that, there is an existing feature request for this.