I don’t think I quite follow.
The same door library part may have different surfaces for separately placed instances. Our surfaces are named such (code + description) so they are a little more informative to the user; and there may be multiple entries of the same code, but with a different vectorial fill (e.g. timber grain direction), which requires a different descriptor. However, in the schedule, just the code is required.
I don’t think I can hard code the surface into the part.
I’m not familiar with master_gdl, as every practice I’ve worked for has prohibited their use. However, I might dig into it further.