Meteor useraccounts : can't force signin form to show up

Hi everybody,

I can not find out how to force the signin form using useraccounts package to appear whatever is the current user state.
{{> atForm state='signUp' always show the signup form, even if the user is already logged in, but {{> atForm state='signIn' }} does not if the user is already logged in.
This behaviour does not sound coherent to me, I’d like to have both form shown as I locked their state, but I can’t find any option to do so.

To give you a bit of context, I am currently trying to implement a demo mode for my app. When the user access the app, I create an user with a dummy username and password on server, and log him on the client.
It allows new visitors to interact with the app ; when they want to save their work I simply fill my dummy user with their email and I send them an enrollment email to set up their password.

However, if the visitor is actually a registered member and simply want to login, it raises an issue since he is already logged as a dummy user and I can’t show the login form anymore.

My current solution is to implement my own login form, but still, the prebuilt useraccounts form is really cool…
The only post I found about this probleme is this one, but it never got answered.

Do you have any strategy to implement such a demo mode ?