I suspect that not having paid this fine would have had zero consequences--even in future trips to Switzerland.
By the way, based on observations in Switzerland, it is ALMOST impossible to get a speeding ticket.
I would take issue VERY strongly with this.
Just three examples.
1. DS took girlfriend and cousin to Lucerne on a day trip from home in France. Two months later, a speeding fine with a substantial add-on for non-payment arrived at our house addressed to my husband, whose car DS was using. We paid up. We haven't quite let him forget it.
2. Many years ago when I was at work in France, two local policemen turned up with a speeding ticket from the Swiss police for my colleague who was often away in a hired vehicle for business purposes. They were serving this fine officially for an event that had taken place 9 months' earlier, but had taken time to track down the driver via the rental company. Fine paid. Some embarrassment, and a bit of teasing.
3. Another colleague was flying BSL-LGW with Easyjet. When he came to the security point where his passport was checked - non-Schengen flight - the immigration officer called the police who then marched him to an ATM where he took out enough SFr to pay an unpaid speeding ticket. It was either that or miss his flight.
These three situations are true and should serve as a warning. Please heed the Swiss speed regulations or you'll find yourself with a tidy sum to pay even if you only did a few km over the limit. And the police WILL catch up with you even if there's a time lapse.