116th and 125th getting too large in NYC Transportation?

[RWERN]

And with Columbia expanding as they are supposed to, I would not be surprised if (either as part of Phase 2 or as a Phase 2a) the 96th-125th Street portion were to be expanded to include going all the way across 125th (with transfers at all stations along the way), ending on a low elevated platform under the 1 at Broadway-12th Avenue (with a portal after St. Nicholas Avenue).

While from a network connections standpoint, having the crosstown connections sounds great, there is (as I'm sure has been explained in other threads) a local fault line running beneath 125th St that could make such an extension difficult or unfeasible.