How to fix a 24fps shot that looks jerky when rendered at 30fps frame rate?
If you change the frame rate of everything to 60fps you'll get an even frame blend every 2.5 (60fps) frames.  If you change the frame rate to 120fps you can eliminate the stutter completely, as 30 fps will repeat frames 4x and 24fps will repeat frames 5x.  But few systems can play 120fps, whereas many can play 60fps (including YouTube).