Lol. 
I think a second more secure canary npub displayed on your primary profile (for which you haven’t put the nsec into any clients) + NIP05 where you control the domain is plenty
(… I should set up my canary npub) 

 Dont forget to timestamp it.

I dont get the canary analogy; the canary is the thing that dies first as an early warning; in your scenario that npub is supposed to die (idealy not at all) last. 

 Yeah- I suppose the canary in my mind was the text on the primary profile referring to the secondary one 

 The more i think about your comment, the more im with you that there’s a better word for this