bvoip has updated and published updated hotdesking templates for the following models:

Yealink T19P E2, T19 E2, T21P E2, T23P, T23G, T27G, T29G, T40P, T40G, T41S, T42S, T46S, T48S, T52S, T54S, T53, T53W, T54W, T57W, T41U, T42U, T43U, T46U, T48U, T30P, T31P, T31G, T33P, T33G

With Hotdesking, you can set a BLF key, clear the current registered user/extension, and then login via the keypad with an updated user / extension. 

You can find a full list of supported devices here.