Default folder location for Prompt for File action?

[ComplexPoint]

Update - looks like there was an answer here:

Go to a Specific Folder in Open and Save Dialogs

In a standard Open/Save dialog, you can type Command-Shift-G, pause, and then Insert Text by Typing a full path, including file name, and then %Return% and that will select a specific directory and file.

(Looks workable but perhaps just a little (Rube Goldberg | Heath Robinson) – I'll script it