If you're referring to "If the main signal is a (train station's) exit signal ("Ausfahrsignal"), this speed limit applies until the last set of points/switch has been passed by the complete train, after which regular speed is permitted.", I think that means "once you see a normally working signal again, if it's of a specific type (the exit signal), you still have to stay at 40 km/h until you have passed all switches.". As far as I understand the article, Zs1 is mostly intended for very local speed reductions, the kind of speed caution relevant to this discussion sounds more like the Zs7 signal.
If you're referring to "If the main signal is a (train station's) exit signal ("Ausfahrsignal"), this speed limit applies until the last set of points/switch has been passed by the complete train, after which regular speed is permitted.", I think that means "once you see a normally working signal again, if it's of a specific type (the exit signal), you still have to stay at 40 km/h until you have passed all switches.". As far as I understand the article, Zs1 is mostly intended for very local speed reductions, the kind of speed caution relevant to this discussion sounds more like the Zs7 signal.