I'm getting a bit bored with this ....

If you are comfortable with the API, you could snag all the collectors that have the "escalatingChainId" value of zero:

    def String collectorsEndpoint = "/setting/collector/collectors";
    def String collectorsFilter = "&filter=escalatingChainId:%220%22";

Then from your responses, just loop through, build the body of patch data that would set that value to the ID you want for the escalating chain (you might have do use the API to see those). And then patch it with the PATCH version of "/setting/collector/collectors/{CollectorId}". Make sure your call to the endpoint with PATCH includes "?optype=replace" as a query param, so you only patch the stuff you build into the json body (just the new escalatingChainId).

Then you could put it in a config source to pull the results of the code running as a config, and hang the config source off a single resource, maybe your portal resource or whatever.

I did look around and didnt see a way to set a default, but I'm UI challenged, so maybe there is one there.