I would never track this using Inventory Item Type. That ends up controlling Average Cost, for Pro/Premier, or optionally FIFO for Enterprise, and none of that applies to Fixed Assets. Sheesh.

You don't even need Items. I have a Fixed Asset listing by running a Quick Report on the asset accounts and the depreciation accounts, from assets placed on service from Purchase or construction data, and then Memorized transactions for depreciation, one of which is Annually out for 40 years. It isn't that hard to manage. I would never mix that into Inventory functions.

I don't bother using Fixed Asset Items, because I cannot bother with FAM, either. It's not that hard to manage manually. I have some customized reports in a Memorized Report Group, for all of this. It works fine.