Many have had this ongoing issue when plotting/batch plotting drawings from advance steel.
There is only a workaround by using file renaming software which is a poor solution.
There have been numerous requests for this issue to be resolved and no headway has been made.
See the attached screenshot and look at drawing 102 this doesn't have the advance steel naming at the end of the pdf.
This happens When using our Prototypes: UK-FOUND-A1 & UK-FOUND-A0.
Therefore there is a hint that this can be done on Autodesk's part.
Yes, I have customised our drawing output name strategy but this hasn't changed/removed the advance steel naming at the end of the file name.