I can't imagine waste plastic being free once it's known that someone is making alot of $ with it. Time will tell. It won't be the first time I'm wrong...
And they can't throw any type of plastic other than 100% hydrocarbon-based material in there (like PE, PP, and PS) without changes to the process (and additional permitting). If it is a true catalyst, it requires specific chemistries with which to interact. They may have to even limit the plastics used based on filler content.
Given the above, I still think they make considerable $ off of this and provide a valuable service. I'm new to this stock but been following it awhile.