Google Compute Engine SSH - different username after switching to OS Login

I asked this question here and got a clear answer.

Why is the username different between OS Login enabled and disabled?

OS Login ties your Linux user account to your Google identity so that you have a consistent username, UID, and other posix information, in every VM you log into.

[...]

In order to prevent uniqueness conflicts across different organizations ([email protected] and [email protected]) the domain name is included by default.

[...]

When OS Login is not enabled, the username is set in your SSH key which has no tie-in to a user's Google identity. The username is generated to be convenient, and none of the OS Login-specific concerns apply.

And can I influence the username when OS Login enabled?

The posix information is immutable for consumer identities (non-G Suite users).

So no, I can't, because I'm an individual and not an organisation.

In the end, I solved the inconveniece this caused me by simply recreating the server with OS Login enabled - that of course is one of the strengths of Compute Engine.