It'd be useful to have a way to make analytics calls conditional on a value returned by amp:access, so that certain calls are only made for certain users.

Although analytics will wait for the result of an access call before firing if you include any variables from access, it does so even if the value is undefined. Would you ever consider making a given analytics call never fire if a particular amp:access returned undefined for a given variable?

i.e. requests: { foo: 'http://foo.com?x=AUTHDATA(donuts)' } would only make call foo if donuts was true or false but not if it was undefined.