I wonder what "pirating" your own software to handle the "free trial"/free tier case would be like? Weird thought, uploading your own software in a particular guise to BitTorrent or something, to allow for free usage but change the expectations of the user...
That said, I distinctly remember a number of blog posts over the years where users using obviously pirated versions demanded support, so it seems impossible to avoid entirely haha
Yet another example how ungrateful many people are towards free software.
The only difference to piracy, is that not only do they not give back anything, they feel entitled to all kind of requests.
So the result ends always being the same, moving to something else.