Let's Control It

I bought a Sonoff Dual R2 module. As far as I know it uses an 8285 processor. I have a few questions.
- what is the pinout, i.e. GPIO`s used for relay1 and relay2, the onboard LED indicating WiFi connection and the LED indicating that the device is on? The latter is probably not connected to any GPIO but is powered directly from the power supply;
- what is the GPIO for the onboard button?
- the module has free solder pads marked as Button0 and Button1. What GPIOs support them? Can they be used to connect an additional button and/or an additional LED diode directly to the module without an additional transistor?
- After soldering the contacts to connect the USB/UART programmer, how to force the programming mode?
- which FW should I compile? Should it be env:normal_ESP8285 with its own Custom.h or the default values ​​will suffice. I just need to use relays, 2 LEDs and 2 switches (as long as it is possible to use the mentioned Button1 and Button2 solder pads).

Thanks in edvance for advice !

I usually take the info from the Blakadder site: https://templates.blakadder.com/sonoff_dual_R2.html (I think it is mostly maintained by the Tasmota team).

I have one running here, and it used to be rather unstable (with an August 2021 local build), until ~3 weeks ago when I installed the most recent build, and now it's been running without any problems.

THX

@Ath

You mean that ESPEasy_ESP82xx_mega-20211224 You found as a stable one?

Hm, I have the Sonoff POW R2 here, not the DUAL R2, sorry for the mix-up.

Yes, it should run fine on the regular December release, though I'm currently running a self-built February 2022 release on my unit. The August build I mentioned was unstable for other reasons, and was never released.

You mean that ESPEasy_ESP82xx_mega-20211224 You found as a stable one?

I run three dual r2 with this build and had no problems so far. A led with a resistor (around 200ohm) is also no problem.

Thanks all for help!