You're probably right, but I was inspired by the previous post by mkrsjak asking for more detail on modding a CC supply to be a CV supply. Generally, I hate answers like "if you have to ask, you're not ready to know" but this is one of those places I think it may be appropriate. There's a lot to be said for trial by fire, but this could literally result in fire, trial, or both. Not that any project in hobby electronics is intrinsically safe necessarily, but if you need help creating a voltage divider, you should probably hold off on modifying power supplies. I really don't mean that to be condescending, just more of a crawl-then-walk thing.
Keep in mind one thing: There are companies of all shapes and sizes that make electronics. I'm sitting right next to a stack of Juniper routers with T1 and DS3 and OC-xx interface cards. They make all that stuff, but... Juniper does not manufacture power supplies. They buy them from established companies that do that one thing and do it well. I expect there are engineers at Juniper that could build one, but the agency certification process and the liability of something goes wrong is such a barrier to entry that they'll stick to simple things like 6-layer PCBs clocked at multiple GHz.
I'm not going to lecture people about their choices, we're all adults and I'm no one's father. All I ask is that -everyone- consider these things when searching for the smallest, cheapest, simplest looking trinket to be found on eBay that says it'll convert mains voltage to.. anything. I hope this is a horse that still has one last breath. 