Frenkie de Jong should be Xavi's big project at Barça.
The good news is, we're already seeing reasonable improvement in his understanding of Barcelona's philosophy, especially compared to our coaches past.
Frenkie's success would be a huge win for him, Xavi & the club.

It would firstly serve the purpose of showing us Frenkie's ability to evolve & adapt to better serve the collective.
We know his talent & profile are unique but can they be moulded to become more fitting?
On the other hand, it would dispell doubts of Xavi's individual coaching.

If Xavi can coach our players to minimise or erase their glaring flaws, it would be a sign of a great coach.
Ultimately, it goes from affecting the individuals to improving the collective.
However, even if that can be achieved for Frenkie, there's always the financial side too.

And that will ultimately decide his fate.
He's too marketable to keep given our financial situation. But I don't think he'll leave in January so Xavi and Frenkie have likely until the summer to make their case for his stay.
The clock is ticking and there's lots to do. ⌛

To people highlighting his flaws, I'm aware of them & no one is denying they exist & (some) are big. That's the whole point.
However, he's likely staying at least until summer so why not work on it?
The upside of his successful coaching is huge, not least in the financial side.