It's supplied under the MIT or Apache licence. You just need to obide by the conditions, there is no mention of any payment.
GoPro bought the Cineform codec for use with GoPro Studio. They then made the whole lot open source when they stopped using it. PStudio used to support Cineform after being nagged by certain people (cough), as long as you had installed the codec via Gopro Studio. Pinnacle they decided to use it to support Transparency, and removed the co-dependence on Go Pro Studio so that you had to have Plus or Ultimate installed.
It's possible that there might be a fee for commercial use that I can find no reference to on the Internet, but I'd be very surprised. It would make little sense for Pinnacle to choose it when there are more common codecs that support transparency, including DNxHD, unless it was royaliy free (or very cheap).
The PS 26 Trial has a number of omissions and control panel options missing. It's based on a very early build of 26. So the missing Cineform might be for the same reason that other stuff is missing.
Interestingly, the new Render file format is Prores, while the old one was a disguised form of mpeg-2. I wonder which one the trial version uses? And which require a licence fee?