You might need to experiment a little to get advanced functions working.

There is a family of code sets, used by Phillips and many other brands, where the basic functions (power toggle, digits, CH+-, Vol+-) are the same across all the code sets in the family. But the advanced functions (PIP, Menu, etc.) are different in each code set.

There are some Advent TV's using a code set in that family, where the PIP function in one of the Philips code sets is literally a self destruct command to the Advent (expensive repair required after it gets that command). I doubt that viewsonic did anything that insane.

If you try whatever advanced functions your Viewsonic supports, I think you'll find the four OFA setup codes differ in what commands they send for those buttons, and fairly likely none of them are right for the viewsonic and you whould need to find the right EFC numbers instead.

But for the main topic of this thread: The fact that some Viewsonic model uses a code set in that Phillips family of code sets, does not mean that some other Viewsonic model is likely to do the same.