I recently USB paired my WP10 with my Win10 laptop and browsed the Windows Device Portal. From the network diagnostics displayed and the fact that my phone is reachable on loopback, it seems to me that it should be possible to write an application to enable the laptop to use the phone's wireless adapter. It surprises me that someone hasn't done this already, so it could be that it's been attempted. While I'm looking through the UWP and .NET APIs for classes capable of it, can anyone tell me sooner rather than later why it wouldn't be possible?
Btw, I already have unlimited tethering with my phone plan, but I'm trying to maximize throughput to my laptop, which I make much more use of than my phone.