Interesting tidbit about the OTG spec, I Googled up on it to finally figured out OTG vs regular USB connections - how something so simple can get so complicated. All for want of an extra port on the computer for charging.
I am running APRSIS on a NuVision 8-inch tablet with Win10 Home. Added a 64GB microSD card for extra storage. Not knowing all the USB/OTG info I went with Bluetooth for the TNC connection(s).
I have a Kenwood TH-D74 HT that supports APRS or KISS TNC via Bluetooth for portable operation and purchased the Bluetooth adapter for my TinyTrack4 TNC for mobile operation. I also have a BadElf Bluetooth GPS. This way I can dedicate the micro USB for charging and use Bluetooth for all data in and out of the device. These connections work great, getting the devices paired up seems to be a trial-and-error process for me though but persistence pays off.
This company (no affiliation) sells many BT adapters, some cost almost as much as the tablet did, but then again the tablet was only $80.
I have to second the warning about screen size. 8" screen is barely usable for Win10, even in "Tablet mode", I have to use a stylus pen to select controls and move the windows around. I have a mini-keyboard/trackpad (also Bluetooth) on the way, maybe that will ease use. Once things are up and running and APRSIS is maximized, the map display is usable enough.
I painstakingly downloaded all the maps for Long Island, NY at a pretty high zoom level for off-line use. Taking off on a longer trip is problematic as I do not have hotspot capability on my phone to get maps as I need them.
73, Rob - KD2GRS