Here's my situation. I finally got a 4K HDR TV (Sony 55X900e), but my home (well - apartment) network setup can't handle streaming high bitrate files from my PC to either my TV or my PS4 Pro.
My PC is in my second bedroom and the TV is in the living room. They are connected via a powerline connector. A hardline isn't an option without getting in the way of walkways (and looking horrible to trace along baseboards and doorways).
What I'm thinking of doing is getting a USB 3.0 external HDD and connecting it to the TV to play HDR content locally. But my main concern is is being able to transfer the files from my PC to the hard drive through the TV.
I could move the hard drive between the TV and PC when I need to transfer, but that would get really annoying really fast. The simplest method while be as I said above, transferring the files over the network using the Android TV, but is that a possibility?
If you don't mind the drive not being readable on other devices without formatting setting it as internal and using an FTP server should work, that's the setup I have on my Mi Box and it works as you describe