I think that’s a great idea! If Sony’s Vegas development team hasn’t been working on the EuCon / Mackie /HUI integration… then, there you go!
Finding the last supported version of EuCon/Mackie that worked with Vegas is the way to go, and that version may still work just fine with your other DAW’s.
I wouldn’t say the Avid Control is a paper weight though… It’s Sony who (if true) stopped development, and the controllers work just fine with other DAW’s that support EuCon /Mackie/ HUI!
Check out EuCon version 2.6, or 2.7.1, the great part about it is that Avid still has all these previous versions on their website.
Al