The thing about an optional RTwP is the resources that would go into it. You would also need to rebalance the game for the RTwP mode. I would much rather those hours went into character development, side quest implementation, spell implementation.
The thing about BG2 was that it gave you everything but the kitchen sink. Nearly every magic item in the rule books, huge chunk of spells, so many side quests . . .
I think the RTwP fans should start lobbying WoTC to use the PoE engine for BG4.
