You are asking if you must declare a path to the HII library (C:\Windows\LDDriverStore) in the unattend in order for HII to work? Is this accurate?
If that's a correct understanding, the answer is no.
HII will copy over the *.db3 file, query the machine for hardware id's, compare to the hardware id's in the db3, and then download drivers that are matches. Those drivers are copied to C:\Windows\LDDriverStore, and DISM is ran (in WinPE, I can't recall what it does when it's in windows), and Windows loads then loads the drivers from LDDriverStore into its drivers folder.
This article goes into some more detail: About HII Driver Selections
I suppose you could use the unattend to read that folder, but in order to get it to read the LDDriverStore, you would have ran HII already for it to copy drivers into that directory (meaning it will have already had windows load those drivers) - so it'd be redundant.
Here's some other articles that may help:
TLDR; You don't need it in the unattend, HII actions in provisioning itself will load drivers that apply.
You are correct in what I was asking. Thank you. We will proceed with not referencing a driverpath in our unattend file. Thanks!