After Heartbleed was announced, a number of tests popped up that let me test if a server I was connecting to was patched, unpatched or unknown. For example, https://filippo.io/Heartbleed/
Is such a test possible for KRACK? Including checking...
- my device 
- my device that I updated over an unknown wifi connection
- the router I am connected to (but don't control)
- the router I own
 I have other ways of finding this out, but here I'm thinking of J. User who hears scary news and just wants to know if their laptop/phone is vulnerable