update on this. after multiple rebleeds and adjustments I've come to the conclusion that the new master is slightly different from the old one (even though it's the factory part).
It takes a bit longer to pick up, and is less progressive than the old one.
(this is assuming that the new lockheed slave that was fitted at the same time is functioning correctly).
Finally have it set so it is not dragging and fully engaging.
ended up with a pedal height that is about 1 cm lower than it 'should' be going by the manual.
Takes a bit of getting used to and makes smooth take offs a bit difficult.
Might get a bit better once I put some more km in and get used to it.