make up any reason you want.
-morphing puts special organelles in your cells designed to gether the proper dna, once you become a nothlit, these are destroyed, but the new ones avoid cells that already have them to reduce energy consumption and make sure all parts of the body are capable of morphing.
-morphing uses your brain as a computer to handle the complicated process of morphing, certain select neurons are permenantly killed or disabled when you become a nothlit which makes morphing impossible but otherwise has no effects on you.
-the zero space mass extrusion system is triggered by energy produced from large differences in average distance between cells in your body, if the energy difference between zero space and normal space is reduced, it creates a permanent link, so any further attempts to apply the morphing ability would just zap both you and your extruded mass equally and fail to reverse the link.
I'm spouting complete nonsense now. its fun!
-in a morph, the DNA of the morphed animal is strictly controlled with strand end caps. these degrade over the course of two hours. when they break down completely, the DNA in use is used in cellular division, destroying all other existing types of DNA. but it does not disable the zero space mass extrusion system. extruded mass acts as an insulator from morphing energy, usually present in modifications to the extrusion system. when morphing technology is reapplied, it simply is absorbed by the extrusion before it can be used to modify any cells in normal space.
-blah blah blah, state of flux, blabbitty blabbitty blabbitty, process of morphing energy thermal gradient detection and interdimensional reduction through radiant form. blah blah, blah, a system of equallizing mass through vibration cancelled out by SCOP radiation... blah, blah, blah, blah, movement of matter through a maintained link through waste of a purposefully inefective negative energy form conversion device of organic origin. BLAH.