Well, we went to my wife's family's cabin and to my pleasant surprise, they've installed DSL, which is pretty dang impressive considering how remote this place is. Up/down speeds are about 1 megabit which is better than the dial-up I feared they had when I first heard that they had internet.
At any rate, I furtively brought my Dexter-related hardware with me on this trip (because why wouldn't you want to work on Dexter while on vacation??) and had a chance to do some work this morning while the rest of the family slept in.
I decided to try to fix the problems with Time Traveler (which basically means adding the reverse-playback commands that I have not added). I am sure glad that I designed the .LDIMG file format with reverse-playback in mind because now it is really paying off. It seems that if you die a few times in time traveler, it will issue a 0x4B command which means playback at 3X speed. This is even if you don't use the time reversal cube! And since I am dying left and right (possibly an emulation bug in Daphne), I can't play the game for very long without triggering this.
So, I am now working on adding the "play backward at 3X" command.