It is not the vaporizer's fault, if you don't bathe you smell, if you don't clean your vaporizer it will smell as well.
Carrying grinded weed in a vape will ALWAYS smell as much as the weed smells and as much as air can leak out of the vaporizer. The MFLB is not in any remote way sealed so that was bound to happen, if you add the gunk that attaches to a used MFLB, it is all but expected.
My suggestion: carry the vape and a contact lens case with weed in it or any other kind of small case that as a cap that screws. Or get a Jyarz for example.
This is not rocket science, weed smells. Grinded weed smells more. Grinded weed in a dirty vape is a recipe for disaster, especially when you turn it on. One of the reasons why i prefer convection based portables.