The z-offset will depend on your machines physical parameters. Adding the switch should not impact the z-offset, but updating the firmware could reset it to default. I will try to update these instructions with steps to calibrate z-offset. Sadly I don't have time at the moment so it may take some time. You might be able to get some help from one of the Facebook groups.

I think they switched to the Robin mini for the QQ-S so no I don't think the firmware I posted is for your machine.

That is all I needed for my QQ.

Yes, rotate 180. The idea is to flip the plastic clips such that the the wire connectors plug in opposite of normal. Do this for each stepper driver that you replace. The stepper drivers that come with the QQ run in the opposite direction as the the 2208s.

I think that the 2208 and 2209 are the same direction, but I don't have first hand experience with the 2209.

The wires stay in their connector. The clip that needs to be reversed is the plastic bit that aligns the connector to the board.

Unfortunately, I did not take a photo when I was doing it.

This step is not entirely clear on how to remove the ribbon cable with the spudger. It seems you need to pry up the black part.

You can either, flip the orientation of the plug on the board, or modify config values in the firmware config file and re-flash the firmware. I chose to flip the plug so I would need to mess with flashing firmware.

Hi Elmo

I don't know where you can buy the cable. It came with the switch when I bought mine.

FLSUN has a new website http://www.flsun3d.com/

Try contacting support through the website.