I am working on a 3D printing project that would allow people to have a way to quickly tap lands in an easy to use and obvious to all the players around fashion. It would hold a max of 15 lands. What do you all think? I can show photos, etc. if you all show interest!! I haven't built a prototype it, I have drawings etc. just trying to see if there is any interest in such a device. I know I have had to deal with some interesting players who claim that they have more lands than they do and it is so hard to keep a clean organized play space when you have a ton of lands out and they get everywhere. Here is a link to the sketch: https://www.pinterest.com/lexi0847/magic-prototype/
If you have a problem with an opponent being deceptive about their board state and refusing to make it clear, just call a judge.
If its not a tournament, dont play with that person if you think they are being shady.