Please tell me if I’m being daft here but…
As far as I can tell the only location of the ‘Change Character’ statues are in the Nexus, just to the top of the central square thingy. However, in my experience you are most likely to need to change characters whilst in your Vault (those of us who don’t have 100 open chests use our extra characters for storage), so I spend a lot of time doing the ‘nexus, walk over, change character, Vault, Nexus, walk over, change character’ dance. Given that there are portals to the Pet Yard, Daily Quest Room and Guild Hall in your Vault, why not have a Change character statue there as well