It is not possible to fire event in another tab/new browser window. For example, query tool can be open in another tab. And thus, changes are not reflected there. There are solutions available like updating the localStorage of the browser but those are not reliable and does not work properly on different browsers.
To communicate between browser tabs we can use cookie polling on client side it self (at least it will avoid polling over http).
The main tab will update only preference specific cookie when preference is updated and other tabs will poll required cookies (not all)
with specific interval (1 second can be configurable).
Polling is a solution but I think it should be the last option. http polls will not be required anyway as we have preference cache in the browser object.
Maybe it's better to poll only when an editor is open in a separate window? What would we be polling for and how would be tell the backend that something changed during the poll?