Is it a possibiliy either with a work around or within the solid edge work flow to:
Create a part component with various hole depths in potentially different faces of the part and when brought into the draft enviroment for the varying hole depths to be allocated there own layer (10mm depth one layer / 8mm another etc..), this would then be exported to dxf (I know i can alter the layers here but i am trying to avoid this as human error is ever present).
Any ideas appreciated, i am a bit stuck at the moment.
I bet you could put the depth callouts on different layers, but if you're bringing a 3D part into the draft environment I don't think you can split it like that. I might be mistaken, but I'm under the impression that the part as shown in the draft environment is a cohesive whole and can't really be fiddled with like that.