My best answer at this point would be that you need to make your own program to find and remove by content. Because no other manual pdf editor would reasonably have such a feature since it’s so niche.
Also vibe coding with AI tends to be very good for singular tasks like this.
I wouldn’t recommend converting the pdf to anything else since that would remove the layer info unless it’s to more complicated formats like EPS, illustrator, etc.
Unauthorized reproduction or copyright infringements is more scary and dramatic than theft in some ways. Just look at the punishment for copyright infringement vs theft. One is waaaaaay more severe. It’s almost akin to saying “You stole his life!” Instead of “you killed him!” Since severity of punishment for copyright infringements is pretty much up there with murder.
Just pay for a good offline sudoku app. It probably costs less than a cup of coffee. Then we’ll all be happier.
I’m with the other person who said it doesn’t really matter. Because it usually doesn’t. Main thing you’re likely concerned with is speed. And most of paid ones have okay speed. So just grab one that’s on sale.
Even if you get one that logs and do all sorts of stuff that someone says is signs of poor VPN, you’ve already become such a hassle to go after that ISP won’t bother.
If you’re doing something super illegal and FBI is gonna hound you for years, that’s a different story. But for torrenting, they’re only gonna go bother the lowest hanging fruits, and you aren’t one of them.
Though, imo, it’s more convenient these days to not get a VPN or torrent client yourself but just get a debrid service to download for you. And then you download directly off of them. Like torbox, alldebrid. Etc. just start the torrent there and you can turn off your computer. Also they cache ton of stuff. So often it’s already downloaded before you even start. I’ve had bunch of cases where I downloaded torrents with zero seeds because of their caching. They also come with whole bunch of convenience outside of torrents. But this is bit outside of your question.