You know; I just realized I should clarify some confusion I myself may have introduced here. My original comment suggests the trigger is always matching a domain regex but domain isn't the only trigger. Content blocker authors can make use of one or more of seven different triggers. For example:

    `load-type`: An array of strings that can include one of two mutually exclusive values. If not specified, the rule matches all load types. `first-party` is triggered only if the resource has the same scheme, domain, and port as the main page resource. `third-party` is triggered if the resource is not from the same domain as the main page resource.

So our concerns about the cat and mouse game is true, but only for domain triggers.