Budget Multi-SIM for Smartwatches

My Apple Watch supports Cellular, but I never activated the feature. The idea behind it is actually practical, since you can leave your phone at home and still be reachable. But Telekom and Vodafone charge almost as much for their Multi-SIM options as an entire budget carrier plan costs, and that was simply too expensive for a nice-to-have feature.

Now I came across WinSIM. The provider is part of the Drillisch group and offers a Multicard as eSIM.¹ This makes it possible to get cellular for both smartphone and Apple Watch for under 15 euros per month.