Why not use Invision Pro Suite?

Not only has it got an amazing amount of history behind it (originally vBulletin), and is so incredibly powerful. I've been able to code in a points system, create all forms of event triggers and code in actions/conditions to create automated processes for certain administration tasks. Always updated, constantly bench tested, used as a commercial product, etc.

It has so much potential, yet the project was to create something from scratch? Are the people building it at least experienced in building forum products??

Check out what I was able to create within a few weeks: https://forum.stake.com/

Look at the potential! You have complete control over the template and formatting of layouts. Extend the API, extend the class/functions/objects, basically do anything you want.