add invocation of authenticatorCancel to step 8 of makeCredential ?

[equalsJeffH]

extracted from: https://lists.w3.org/Archives/Public/public-webauthn/2016Jun/0070.html

Assuming that a system has recognized three available authenticators, when a makeCredential() request is called all three authenticators will display a message asking a user to approve making a credential. [...] what happens when the first authenticator succeeds? If a user selects ok / yes / approve, do the other two authenticators still display their confirmation messages and allow additional registration responses? Or should the client send authenticationCancel() to the two other authenticators after the first successful result?

To a fair degree this is all up to "the platform" (OS+UA+authnrs), I
think, although invoking authenticatorCancel on any remaining
issuedRequests entries /could/ be added to the last bullet item of step 9
in..

https://w3c.github.io/webauthn/#makeCredential

..as you suggest, but others should probably weigh-in.