ESP8266: Is the native non-os sdk supported?

I have installed the PlatformIO and started playing around with my ESP-12E board.

In the past I have been using the Lua environment, but I would like to switch to the non-OS SDK.

Is it supported or not?

I got a bit confused, though. When I see in your online docs, I don’t see the SDK listed as a supported framework; there is only the RTOS SDK.

But then I saw the project example titled "esp8266-native " which seems like the framework I need. However in the platformio.ini file there is no framework specified at all.

If you omit framework option, PIO will use native SDK.