SVP generates extremely small num_frames for script clip

When diagnosing AVSF issue 47, I noticed that when playing a 24FPS video, and use FRC 25/8, the script clip video info's num_frames is always 26333. This number is so small that since it maps to source frame 8395, the video would freeze at about 6 minutes. In fact, other ratios such as 22/7 generates smaller number (e.g. 456455) than the one I put for source clip (10810800), but big enough to not cause issue.

My question is, why does SVP shrinks the num_frames when the FPS is increased by it? Is this some kind of overflow problem?

Also, in the same issue, I noticed that when I set my monitor to exactly 75Hz and SVP to "To screen", SVP chooses to use 22/7 instead of 25/8, for 24FPS video, where former results in 75.4286 FPS, but latter is the better 75Hz. Only if I lower my monitor to somewhere like 74.8Hz will it use 25/8. Is this a bug?