Well, the good news is that they fixed the issue of VI clearing the data tabs when changing data source (v4.5). The bad news is that they fixed it by not allowing you to change the data source at all. But that is easily worked around by creating a new VI, then copying from the old VI and changing the data source at that point. Cludgy, but workable. I would bet that this work around is functional in older versions VI. I agree what a PITA when your data fields are blown away....
Are they using VI for EXPORTING? It sounds like it. If so, I guess my question is why? I gave up on VI exports in 2005 when that version of MAS would not write the header description of the column. Once I learned how to do the Excel query, I never went back. And once you figure out queries, you are half way to learning pivot tables......
And regarding future plans for fixing this, you should ask the customer to develop a request to Sage and justify it by the amount of recurring revenue this will generate. Good luck breaking the news to them!