Not knowing exactly what your needs are here are some alternate suggestions.
Settings > Accessibility > Zoom > On a 3 finger tap zooms and unzooms the whole screen.
Settings > Accessibility > Magnifier > On Lets you use the camera as a magnifier with a slider to provide different amounts of zoom of anything you point the camera at. Then freeze the image and screen capture it to Photos.
Ooh, I must dust between the keys!