Recently, the technical director of Larian Studios spoke with EDGE. During the interview, Bert van Semmertié said that the studio was able to eliminate some of the technical limitations that were in Baldur's Gate 3.
The restriction on transitions between acts (in multiplayer, players must transition all together) influenced how Larian builds the world and the structure of the story:
For a long time in multiplayer, we had a limitation: players could not transition between acts separately. The whole group had to transition at the same time, and this influenced how we built the world and how the story should be structured
In the new part of Divinity, the developers were able to solve the problem with the transition between acts:
In the next version of our engine, this limitation is completely eliminated. Now there are no restrictions on the size of the act.
Bert van Semmertié also explained that Larian Studios is "deliberately staying a little behind the cutting edge." Baldur's Gate 3 does not have "top-end" graphics, and this is done deliberately. This approach to development allows you to stay within the capabilities of the studio.