This is super-interesting. I've always been at odds about "Advanced Options". Somehow, the word 'advanced' has an intimidating aspect, as it makes the user, if he/she has never used it before, fear that something difficult is about to be asked from them. Similarly, there can be a fear on the user's side that mistakes might occur in this section because of its 'advanced' status. The result might be that most users actually never access 'Advanced Options'.

As you explained in the third option, scrolling down to fill out relevant fields and having a save option makes a lot more sense to me.

But I wonder whether the term 'Advanced Options' is actually misleading. Maybe this pull-down section should be titled as 'Secondary Information', or, 'Additional Options', or 'Anything else you like to add?'.

In general, we use very generic language when presenting form inputs. Maybe we need to look at the language structure of a form as well.

Great article!