I am all for this new initiative and starting tomorrow will also add this new STOU in my products. My products will be or CU/PU most of the time, but sometimes PU only. I always require credit (yellow button). My products, even commercial can not be made into tubes or shapes for distribution, therefore the added purple button "limited".
That means from now you"ll find in my zips a word-doc next to my normal TOU (which is still included for those who don't have Office) and in the zip will be added a graphic of one of these two keys, depending if it is CU (green large button) or PU (blue large button).
This should make everything easier, especially for you if you download my products.