I have not with the special pass but : Basel Bad Bahnhof is the official border point and the station is DB property so it feels even more like Germany.

Here are the list of official border points : https://de.wikipedia.org/wiki/Grenztarifpunkt?wprov=sfla1

Simply remember that you can only travel on 2 of your pass days in Germany. To connect to Basel SBB (border point with France) buy a 3.80 CHF full-fare ticket valid on all trains (incl. ICE), trams and buses for 1h.