ian-lr

@bretg I like that approach better! I wasn't sure how much flexibility we have on the vendor macros, but this is more approachable and simpler from my perspective.

@SyntaxNode From my perspective, that would work well. I would suggest throwing an error unless there is precedent (other macro validation?) to do things differently. In most cases, I'd expect...

Base64 JSON blob works for me. To illustrate, something like: `let encodedEids = btoa(JSON.stringify(pbjs.getUserIdsAsEids()))` will be sent through, then PBS will do the equivalent of `JSON.parse(atob(encodedEids))`?

@pycnvr Good question. Could you use something like https://amp.dev/documentation/components/amp-access/ to get user-specific data without invalidating the cache?

@pycnvr OK, let me see if I can experiment a bit with this and see if I can get the cache working, too.

@bretg I found this AMP Issue tagged with `INTENT TO IMPLEMENT` that, depending on the implementation, could be useful: https://github.com/ampproject/amphtml/issues/28095

@bretg Returning back to this, do you think that we should hold off until the eid permissioning is locked in before proceeding with the suggested straw here?