23.976 fps at 1/48th is still within the margin of safety - I mean, if you look at a 60Hz AC pulsing lamp on a waveform, at 23.976 fps you'll see a tiny bit of flicker but for the most part, it's really mild.
Kino ballasts have a very high flicker rate, much higher than 60Hz, so flicker is not an issue.
Most of my digital shooting has been at 23.98P and I hardly have any flicker issues with magnetic ballasts unless there is something wrong with them. In fact, that's one of the advantages of digital, it's so much easier now to spot a bad ballast on the monitor or on a waveform, and sometimes you can fix the problem by changing the shutter speed -- often when there's a problem, using 1/60th for the shutter is enough to get rid of the flicker.
