Neither dangerous nor silly, but it does have a few issues that I don't like:
- The minimum height you can drop this apparatus down to might not ever work with a lot of vehicles that have lower ground clearances.
- The location I want to lift the vehicle from may be a different point from where I want to support it with safety stands.
- The ones you linked on Amazon cost a lot more than the individual bottle jack and safety stand.
At $86 it is a lot more than a $25 bottle jack and $50 jackstands, although maybe some people can afford the $11.
Honestly, those things look kind of slick to me for the single use of tire swapping, for those of us who have to do it a lot (like me). The height range is clearly listed, the environment is usually controlled (like a garage, let's say), and the whole deal is a nuisance with lots of clambering. It also serves the purpose of being yet more stuff, which is the GJ way. Heck, I've even got a 1/2" impact mostly just for this, which certainly costs a lot more than the factory lug wrench.
The first line of the original post: "I swap between summer and winter wheels on multiple cars, multiple times per year."
and optimizing that is an interesting problem. No point in feature creep.