It might seem just mildly interesting to some, but this is a very good idea.
I normally know what chain belongs to the light and to the fan, but for some weird reason I often end up pulling on the wrong switch. This is especially true after my dad replaced a broken socket in the kitchen, so now I keep confusing the chains.
This might not look like much, but it’s actually pretty clever. You can find these chains at Lowe’s, and you could say they take care of the guess work, at least as long as nobody installs in the wrong switch….