If you really rework the BI, the why not a more fundamental rework of Burgundy?
- Start by removing Philipp as a starting general. (There is this the bug in the game that treats starting generals as if they been generals since they were born.) Then Philipp usually lives until the Shadow Kingdom fires and Charles doesn't suicide against Liege. (Of course fixing the general bug or making Charles not a bold fighter would also work

). In real life Philipp dies in 1467 and not in 1445.
- Flanders as a PU but not Artois or Luxemburg treats these entities in an inconsistent way. Flanders was a PU as of 1385 (at least according to Wiki). It seems that it was integrated into the "Burgundian State" in 1386. Luxemburg was only added 1441 but is a province ingame. So why not model Burgundy differently?
- For example, give them all the PUs. Introduce some base level of autonomy (like the great privilege does now) or model the unrest the centralisation causes, as an unified Burgundian State in 1444 will be probably be OP. The struggle between Burghers and the Crown could fit nicely into a slightly reworked mission tree.
- The alternative would be to separate all of them into different PUs like Beyond Typus does. The problem with the last approach is that Burgundy becomes underpowered (or maybe totally OP given an expanded vassal swarm) and probably unmanageable for the AI and novice players. It also would make the centralisation so much more difficult.
- If you don't want to change the structure of Burgundy, at least fix the PU dates so that Flanders can be integrated right away.
- Philipp was also a Duke inside the HRE so Burgundy should be able to attack HRE minors without the Emperor interfering. This is really just an ingame problem because of the HRE mechanics and the fact that we cannot play Philipp, Duke of Holland ingame. Deus Gratia recently modelled this nicely by moving their capital inside the HRE.
- Last but not least, the BI has become unreliable - the Emperor often doesn't demand the lowlands but simply gives up. That's annoying for the player as one can't grant the "Great Privilege".
- As a bonus, Deus Gratia modelled the purchase of Gelre and Further Austria nicely - these could be nice mission that would add flavour to the mission tree.
Edit: I didn't have time to play the patch yet, so if you have fixed Philipp/the general bug I apologise in advance. I just assume that it is still there.