MCC command 10033 is mapped to the "Menu" key I was speaking about, and is usable for both DVD and BluRay discs. I have it mapped to Ctrl+Sift+M as explained
at this location. My experience is that it will not get you out of previews on all BluRay discs, only on some. This is why I said the disc may have to be authored to allow jumping to main menu while previews are playing.
"Switching to title playback" means "playing the disc without menu support", not "playing the disc with menu support but skipping straight to movie start". You can pick which way you want to play BluRay discs (with menu support/without menu support/ask every time) by configuring the "Play Blu-ray discs using Menus" setting. I have it configured to Ask, so that it will always ask me what I want just before a BluRay disc starts playing.
I never tried the "next" button for navigating BluRays in menu mode, I will try it too!
I still think the easy fix for skipping when the skipping duration is larger than remaining playback duration should be implemented though. A freeze in such a situation is not expected behavior.