So, I have a lot of coins. I like to collect coins. And these are just rattling around in a box. I went to the hobby shop with the wife and I was looking at the coin holders, so that I could organize my coins, right? And then my wife says "Why don't you just print it?" (Light bulb goes off). When I get home I look for a good file on all the typical places. Nothing. Wife: "Just model it yourself". What a great idea. I had a hard time trying to get a good lid. The ones you buy have a tight fit lid that presses on. But I wanted better. So these have hidden cavities for 6mmX3mm magnets. If you want to insert gcode to have the machine pause and eject the build plate, set a color change in your slicer and then replace M600 with this:
G1 X10.000 Y200.000 E0; parking position GET THE PRUSA TO STICK IT'S TONGUE OUT!
M1; user stop
M105; return to current temp
Now, I use a Prusa, so I don't know if this will work for yours.
The lid and the box have hidden pockets for magnets.