Amazin!
27$ for something that already exists for free.
I understand the difficulty in programming stuff especially for larger user bases and am willing to pay a few bucks for extensions (see DeArrow for example). But 27$ is too much, sorry.

And also you are not upfront about it. I only know it when I 1. Downloaded the extension, 2. Downloaded the companion, 3. Downloaded a video
That is absurdly misleading. You could just show a prompt on installation of the extension or even better at the top of the extension description in red so everyone knows what they are getting into.