Ian KD8CEC has announced a beta version of his firmware (Version 1.12) for the uBITX V5 board. He has written an article about it here.
All existing firmware functions for V3 and V4 are available on the V5 beta.
The same version of uBITX Manager will work with the v5 Board.
Only the LPF control and the frequency control part are changed in the V5 code. Ian has released firmware V1.121 for V5.