That looks about right. The slide switch can touch the adapter board as long as the solder points don't touch the case of the switch (would cause a short). I assembled the adapter board, switch, and header pins as you have pictured here. However, the whole structure may need to be lifted off the main board a little bit so the top of the switch casing is at the same level as the top of the pots. I think it'd be best to have the board installed into a case or faceplate with the pots fastened to that, those header pins not yet soldered to the main board. That would help you line up everything before soldering. Worked well for me. For this and other builds, I always use either a drilled case or faceplate to line everything up including pots toggles etc before soldering any of those components.