So you’re sure there’s only 24fps on the Digibeta – so that it looks like it’s running fast when you play it back? because digibeta must run at 29.97, and very few video systems use that 24fps on a digibeta trick.
Then in that case, capture everything as 29.97 fps into FCP, and then have Cinema Tools conform the frame rate of your clips to 23.98 without doing any pulldown conversions.
presto!