ZO_ScrollList is not a wholesome library and ZOS is not a charity. It is merely a tool made for a specific usecase by a company trying to make the most out of their time. It doesn't do anything besides that. If you need extra features, you will need to implement them yourself. That's how it is with almost anything related to ESO addons.
Do you mean the starting position of the scroll list?
If so, you could use
Lua Code:
ZO_Scroll_ScrollAbsoluteInstantly(myScrollList, 100)
to set it to the very bottom.