Without drilling out that hole, but doing the rest of the kit, does it still apply any extra pressure on the torque converter clutch?

Yes it does, the lock up hole is only for making the lockup occur faster. By faster I mean more snappy, not at a lower rpm.

Ah...so the hole provides a more abrupt lockup sequence, not a stronger lockup...right...?

the holes through the plate where the valve go in are how fast the lockup occurs, the one hole through ght plate on the top of the vb is apply pressure for the converter. bump that one right up.