Mlem can’t be afterblep, because blep doesn’t imply a blep to stop. When you blep a tongue remains in a blep position for an infinite amount of time or until something from the environment like a finger unbleps the blep. Though keep in mind that you can view mlem is a “momentary blep” of some sort, which is of course an absurd statement, but it explains why mlem can’t be afterblep. Yet you should remember that blep can follow a mlem if tongue has to stop in a half mlem position for example. You can also stop the mlem altogether and blep instead. There is no way blep could become a mlem. If you decide to unblep then it wasn’t a blep to begin with, but a really slow mlem.