You need to remove the residual line pressure valve from the master cylinder regardless

The pictured valve is a switch to operate the light on the dash in the event of a brake failure on one circuit
I does no proportioning... so it can stay or go
But rego wants a light to work... so I'd leave it in
If you find the rears are overbraking... which I doubt will happen... you can fit an aftermarket adjustable valve to tailor the bias if required