Please don't alter your unit. We carefully test our products to ensure they're safe and work just as they should.
For instance, if a unit comes with casters, we test it with them, and if it doesn't, we test it without them. We can't guarantee the structural integrity of a unit if any changes are made, so we kindly advise against it. Plus, keep in mind that any modifications would void the warranty.
The only exception to this is adjustable shelves. They don't affect the structural stability, so feel free to add or remove them as you like!