Could FutureDMD be used with VP somehow - does anyone have the source?

Well, it does not make sense
Tell reason for something

FutureDMD seems to be far more flexible for original gaming. The ability to put graphics/scores/text anywhere on the dmd via a script call. VP alternatives like UltraDMD are very limited in what the API will let you do. Basically, 2 Lines of text and an image/video. Nice but not nearly as capable as FutureDMD. (If I understand it correctly)
eg from the howto "[bf][f4][y8]FUTURE PINBALL[f1][y25]CREDITS 0[f4][/bf] is not possible with UltraDMD or any VP DMD software out there.

Gauntlet lover modded Macro's pinDMD , which currently is capable of even more (multicolour DMD's)

So to obtain source code for VP purposes, you would have to ask Macro...