True if someone steals it you would not be able to obsorb it but with transmutation you could simply either create the object 1 inch in front of you so that you could use self matter obsorbtion or if they actualy steal it you can easily simply create another one and besides if the object is handheld size you simply use transmutation to transmute the object in your hand so that it is already touching your hand so you can obsorb it right after you transmute it into the multiversal machine.
*facepalms* I forgot to add the another aspect of the knowledge the power grants. Like Time Travel knowledge, if you meet someone with latent Multiverse powers, then you'll know how to awaken those powers/train them. And you'll know how to jam/disrupt multiverse travelers using machines or powers to travel.
True, except I get the feeling (could be wrong here) that Self Matter Absorption requires contact with the to be absorbed object. If that's the case, then if someone is able to steal a machine you make before you can touch it, then you won't be able to do much about it. And I think Transmutation would let you make most of these without knowing how they worked anyway.
If Superpower-Multiverse Travel Knowledge was combined with transmutation and self matter obsorbtion you could actualy create any multiverse travel device you can imagine so the technoligy doesn't have to be their and thanks to self matter obsorbtion you could simply obsorb the device so their is no chance you would lose it and you could use it at will.