If you encounter problems with this preset - especially with the "opening 2 finder windows side by side", please try to toggle the setting: Finder preference > General > Open folders in tabs instead of new windows. (thanks to tosbsas@BTT community)
There is one condition that might cause the scenario you saw:
Do you have a virtual desktop and you have a second Finder window opened in that virtual desktop? To find out, in Finder, click the Window command and see if there is more than one Finder window opened (please see screenshot). If that's the case, close the other Finder windows and try again.
I'm not a programmer and I just copied/pasted what I found on the internet and managed to put them into a preset for my own use (plus sharing them on github and here in the BetterTouchTool community). If you have other questions, please don't hesitate to ask. I will do my best to help you.