Earlier quoted context omitted.
Not a historian so I may be missing something, but how would one possibly differentiate between the origin being the Dead Sea or Jerusalem based on things like materials used? I mean, Jerusalem and the Dead Sea are less than 35km apart (according to google). Even thousands of years ago, it would have been a non-issue to transport materials or techniques between these two locations. I can't imagine that our knowledge…
Yeah the scale of trade always seems to surprise everyone. It's hard for me often to understand how folks draw the archaeological lines here. Materials could have been traded and the scrolls written near the Dead Sea ... or even folks from the Dead Sea traveled to Jerusalem, used local materials and made some scrolls, and traveled back.
As for the movement of writers, or the scrolls post creation, you'd look at where scripts were generated and where they sourced their materials. Just speculating, as I haven't read the background material on this new discovery, but it would make sense that the monasteries in Jerusalem would have a reproducible sourcing process since they would be generating manuscripts often. Same would go for monasteries around the Dead Sea.