Do you get the same problem if you map the printers manually?
Quite an important question that one.
If you map the printer manually and you get a similar delay then there is not much that you are going to be able to do with it scripting-wise other than avoiding the mapping in the first place.
If you cannot avoid the delay then one option is to split out the printer mapping and run it as a background task so that it doesn't hold up the main script. The printers will appear as the mappings complete, and in real terms it is rarely a problem for the user if the printers appear three or four minutes after they've logged on.
