Use Attributes As Personalization Fields

It would be really useful if attributes were available in the personalization merge tool, alongside name and email. I'd use this often in URLs, so I could send data to another page (like Typeform) to prefill a field. It would also let us customize individual elements like headings to the audience member's circumstances. Lastly, for attributes like a member's stage or level, it would let us build user segments in Google Analytics based on those attributes' values.