I liked the idea. They don't use much plastic and print pretty fast. But the magnets I found were bigger, 6x3mm Diametrically Cylinder Magnets. That type of magnet works really good. No worries if you got them in right. They just work.
Here's where I found mine
200 Diametrically Silver Metal Cylinder Magnets 6mm
Since 200 isn't enough to fill all the tiles with 6, when using ocean tiles, I also made bases that only hold the exact amount you need. I rounded the edges without magnets so it's easy to tell which side has them and which doesn't. I also plan on adding hex storage boxes, for the player pieces, that will snap on the edge of the board. That way they aren't all over the place when playing.