PREFIRE

Hello, Steam has released an update that allows you to create a .maFile without a phone number (at least on a real phone). 
Is it currently possible to create .maFile without number via node-steam-user (5.0.4) or any of your other modules?
Many thanks!

This is great news, I'm glad Valve is no longer locking a security feature behind a phone number.
It appears that steam-user and steamcommunity both just work without a phone number. When you'd normally receive a code via SMS, you get the code sent to your email instead.

Probably not. Historically, logging into the client after verifying your email is what auto-enabled Steam Guard and there's no way around that.

Mail guard is activated after the first steam-user / steam app logOn, this refresh_token is only for web uses.

I'm not sure what circumstances automatically enable email Steam Guard. If you already have a valid refresh token, then yeah, you can use steam-session to get new cookies.

You can't log on with SteamUser using cookies; they're only for web sessions, which SteamUser isn't using. SteamUser will automatically save your machine authorization as long as local storage is available (which it should be in most cases), but if you need to manually handle machine auths, check out this section in the docs. You can also use a refresh token to log on, which is sort of like SteamUser's version of a cookie. That's documented here.