The ESP8266 (and ESP32) is a great chip: powerful, versatile, cheap, easily obtainable. But it's a little bit fiddly when it comes to programming the development boards and transferring the files onto and from them. You have to install the drivers (good luck if you have a mac), install the flasher software, get the flash parameters just right, get the boot pin low (or make sure the auto-reset circuit works), etc. Individually, each of those steps is easy. Together, they make it hard to simply just start coding.
Wouldn't it be great if there was a development board that, instead of the dumb USB to serial converter, would sport a small and cheap USB-capable microcontroller, just like the Arduino UNO or Micro:bit, which would let you simply copy files over to a USB drive it would expose?
That idea is not mine, of course, I heard it for the first time from @tannewt. But I really want this to happen.
However, I know almost nothing about USB, and this is very much a research project. I expect extremely slow progress and possibly shelving of this project later on. I believe it is possible to do what I want (at least the filesystem and serial access), but I'm not sure I have enough experience to pull it off.
All help is greatly appreciated!