I'd just move on. To be honest sites with those types of paywalls should not be indexed. The loophole you are taking advantage of here is a bait and switch by these sites. They want the search traffic but don't want public access. Most of us have already adapted, however, and avoid these sites or pay for them.
Your plugin title blatantly describes that you're avoiding paying for something they are charging for so even though it may not be illegal it's not something I'd waste energy fighting for.
How is that bait and switch? Their content, their rules.
Its like saying some people get Nike shoes for free in exchange for a review. And when I ask for it, or even take it, they have a problem with it.
I think with physical goods we have an innate understanding of what constitutes as theft. Just because the distribution cost is zero doesn't make digital costs free-for-all.
It is a strained metaphor. What I was trying to say is that clicking on a search result and getting a paywall instead of the content alluded to on the search page is not expected behavior to the end user.
Your plugin title blatantly describes that you're avoiding paying for something they are charging for so even though it may not be illegal it's not something I'd waste energy fighting for.