Why are available task types in Journeys different than on the Create Task page?

Summary:

The Task Type list of values is different depending on where you try to create/add a task to a Journey, why is that?

Content (required):

If I create a task on the Create Task page (MCG -> Checklist Templates -> Task Library -> Create), my list of available tasks is much more extensive (screenshot 1). If I create a task through the Journey interface, I am limited (screenshot 2). Why is that? Is there no way to have the same expanded list through the Journey interface?

We are trying to give our service center the ability to add a digital signature task after a journey is assigned so that once it is signed it will be stored in Document Records. This is a unique document to each new hire so we can't just add a generic document to a task that can be assigned as a predefined task. The Task must be created each time with the unique benefits enrollment information.