Independent vs Major Brands Club Fitting

Hi guys, not sure whether this topic has been discussed before?
In the market, major brands like Ping, TM and Titleist offers custom fitting.
There are also other independent club fitters.
Can I know what are the differences between them?
Am I right to say that cast iron cannot be bend?
If so, say I want to purchase a TM CGB, how can they adjust my iron lie to be say 2 degree flat etc etc?
Thanks all