Since it was announced that 4.1 will bring us Kaliyo and Bowdaar as the next cross-faction companions I really wish we could have access to the other factions companions customizations. There are vendors on Taris, Ilum, Belsavis, Balmorra and on the Fleets (Collectors Edition and Security Key vendor) that sell certain customizations only as BoP items.

My suggestions:

A) All companion customizations (the only exception would be CM stuff) should become Bind on Legacy, so it would be possible to mail Bowdaar customizations to Imp toons and Kaliyo customizations to Pub toons

B) Create three customization vendors on Odessen (normal, Security Key, Collectors Edition)

C) Sell Imperial customizations on Republic vendors and vice versa

There is also a reddit thread about this topic: https://redd.it/3v46qx