I would like to replace certain title sets with a black screen as a placeholder such that I can reduce the size of the image I want to burn and keep the same menu structure of the disk. I might want to replace the main movie title set or extras depending what I want to keep or throw away.

I've created a 3 second black screen and an associated vob for it. What confuses me is what I need to do in Ifoedit to get the ifo's and vob's right.
Consider this example where the main movie title is:

VTS_04_0.IFO
VTS_04_0.VOB
VTS_04_1.VOB
VTS_04_2.VOB

I would suppose that to do this I would copy my black screen vob to the _1 and _2 vob's. Then I would Ifoedit the VIDEO_TS and get VTS sectors. This doesn't seem to work. I assume I'm not doing enough with ifoedit or something else wrong. When I play the movie, it gets to the black screen vob, plays it, then just stays on it. It doesn't seem to know where to go to next in the program chain. What am I missing here ?