STA Object In Session And Thread Affiliation

Here's a question that I've not been able to get a definitive answer to.

Creating an STA object (such as a typical VB6 object) and assigning to the
ASP Session store is a bad thing.

It's a bad thing because it forces IIS to affiliate the Session with the
Thread on which the STA object is created.

This means all subsequent requests for that session can only be handled by
that worker thread and can therefore result it in poor performance as
requests queue up to access the thread they are affiliated with.

My question(s) is/are this:

Is this affilation now set in stone for the life time of the session?

Does removing the STA object from the session remove the affiliation or is
IIS/ASP just not that clever?