Just to put my two penn'orth in: I don't know anyone in the UK that uses a 2-stage regulator for lampwork.
I think the standard setting for a 4 bar propane reg is 'full less half a turn', about 3 1/2 bar. I leave mine set to that all the time, and just turn gas on and off at the cylinder.
Glad you got the oxy sorted. There are some good videos on Youtube for oxy maintenance.
Keep on melting!
Moira