It seems to me that when Vinnie moved away from battery products, battery powered audio lost an important high end audio supporter...which means that for the most part, the demand must be pretty low. I think this makes them kind of a one off product where anyone who really wants a battery powered device goes to Vinnie or Tommy or some else and negotiates a deal to make this product...and yes, it will probably be expensive with no absolute guarantee as to the sound.
As to the cable discussion...why would any designer...Tommy, Vinnie, Frank VA...or anyone else knowingly offer their products with internal wiring or power cords that they know are less than they could be if "better" wiring/cabling were used? Yes, some people like PS Audio suggest that you step up to their "better sounding" power cord....yikes...why would you not make that the standard and increase your price?
So, where does that leave us...my thought is that Tommy and many others offer the best sounding products they can make...and if their customers either hear....or think they hear....better sound from any of the dozens of high end cables, they are free to swap them into their system, write about them on various forums....and be happy with their choice. But that in no way means that Tommy should change what he is doing unless he and his own evaluation panel conclude that "surprise...and probably wow...cable X actually does make a meaningful difference".