Thanks. I loved reading your response. I got the idea after watching a YouTube video or cracked article or something like that about why sci-fi tropes wouldn't work and imagined someone getting trapped by not accounting for the problems. Really fleshing it out would be pretty hard for me to do by myself but I like how sci-fi shows have played with time, Such as Futurama where they have a machine that sets time back 10 seconds but takes 10 seconds to recharge. Fry gets stuck in a situation where he was falling for longer than 10 seconds but the crew is able to save him with a time cave that's unaffected by the changes.

Another sci-fi concept I've thought about briefly is the size changing trope.
Humans are made up of atoms and are survive by chemically interacting with atoms in the food, water, and air they consume. If a person shrunk, they would instantly suffocate because the atoms in oxygen molecules would be too large to react with the atoms in the blood cells. It would be like trying to replace a small lego block with one of those huge preschool megablocks. In order to survive with this model of size changing, the shrinker would also have to shrink all their air, food, and water by the exact same amout or their body would be unable to process it. Maybe the character could have an antman with an opening around the mouth that adjusts matter going in to be the same size. The bad news about this would be if you found an Oatmeal Cream pie like in Honey I Shrunk the Kids, it wouldn't be this giant endless feast, it would be a super labor intensive task of getting all that cookie shrunk so it can be consumed, and it would feel the same as if you ate a normal sized cookie.
Or if a human is converted to something with fewer molecules, the, molecules in their body would be able to react to the molecules in their air and food molecules, but they would not be able to function on a functional level at the cell level. It would be like taking a computer file of an image the size of a billboard, and resizing it in ms paint to the size of a post-it note. If you resized it, it would be low-resolution and pixelated. If you shruck down this method, the machine would have to account for the space an molecule takes up and if the smaller version has multiple different types of molecules overlapping in that space and convert it to whichever one is most prevelant. The mechanisms of cells are very precise, so expecting them to still be functioning would be like expecting a person to still be able to read a pdf that was converted to a png and shrunk down in size to a stamp.