Hello,
When I was in physics studies, magnetism was one of my favorite. There are a couple of things you can do for this. Having the wet side and dry side 1/4 inch further apart will not affect it. It’s spinning based on the inner and outer magnets inside the wet side. The motor than attaches to the glass and dry side which produces the electric magnetic field. So do to that, moving it further away will not affect it. (Common sense please if you move it a foot away etc yeah it’s not gonna work unless the electric magnetic field is much higher. But 1/8 of an inch no. To make a magnet stronger two ways are pretty simple. If you have a much stronger magnet rub it across the one you want stronger. Very important to rub it in the proper direction, aka North Pole or South Pole. Another is you can have another magnet added to increase the strength simply by adding another magnet between the glass and dry side. (Don’t believe me

get to magnets on dry glass. Use a deck of cards cut into strips. then add something of equal weight piece of metal whatever. See how many cards it takes before the metal drops. Then start over but this time add the second magnet with the correct poles. You will be able to place more cards between the magnets and metal. Adding a magnet does not make the first magnet twice as strong it simply makes it stronger than if it was the only one. This diagram will help explain why moving them further apart won’t prevent it from working like it should. Again common sense of one says well I moved it 5 inches away, yeah probably won’t work unless you increase the magnetic field. The spacers that have been mentioned do not do anything except prevent the Matt from scratching the glass or breaking it.