This is great, so far I have only seen hardwired options, never seen someone do a expanded battery mod for their smart lock.

Battery eliminators are the way I hardwired my smart locks. You can find these on amazon in various battery sizes and combinations. Combining this with a Voltmeter Adjustable Boost Modul, doing some wireing, and plugging all this into the wall means no battery changes every 3-4 months.