I like the idea, but it’s a solution in search of a problem, and - it’s also got a couple of issues of its own. Looking at the news article about Astronaut Greg Chamitoff’s homemade Velcro chess board, I see that BYO magnets are not permitted, and the weight of the metal plate might also be a no-no.
Instead, get some dice, apply (as appropriate, either hooks or loops to complement the chess board) and roll them onto Greg’s Velcro covered chessboard. And as a bonus, they take up little additional space, stowed with the chess set.
