Confusing use of words, "bootstrap sign-ins”

[maxhata]

4.2 Account Bootstrapping Using a FIDO 2nd-Factor
Once they register a roaming authenticator, users can now secure their bootstrap sign-ins by using this authenticator as a 2nd-factor during sign-in.[12]

To understand what is meant by "bootstrap sign-ins", readers need to go back to the definitions that look somewhat circular.

Account Bootstrapping: “Bootstrapping an account on a device”, or “bootstrap sign-in”.

Signing in: This can refer to either account bootstrapping or reauthentication. When in doubt, we will use the latter, more descriptive, terms in the sections below.

Logging in: see Signing in.

It will be very hard for average readers to understand what this exactly mean.

For this part, to make it easier for average readers, can we simply say in such a way like the following?
Once they register a roaming authenticator, users can now secure their bootstrap sign-ins by using use this authenticator as a 2nd-factor during sign-in.[12]