that I'll probably do myself unless someone convinces me it's a bad idea:
a way to link tracks. when we see a track that should lead into another, play it. When we come from a track other than the one before this track, if this is a child-only track, skip it.

Ah, the classic Brain Damage - > Eclipse, Heartbreaker -> Living Loving Maid, We Will Rock You -> We Are the Champions problem. Actually, it could even be extended to more than 2 songs. Could even address the lack of a "Never Randomize Contents" flag, if implemented properly... You could just chain a bunch of songs together.

Hmm.

[Bar Napkin Design]
1. I guess lrctool could be modified to support the creation of two ID3v2 TXXX (user defined text) frames, like NextFID and PrevFID.
2. emphatic then loads up the ID3v2 frames when the song first comes up, so it could read in these frames to figure out if there are any links to other songs.
3. If there's a "NextFID" defined, then it does an "Insert" of that FID. Easy enough.
4. If there's a "PrevFID" defined, then check if the last song played was that FID. If not, then we came in in the middle, and should skip this track entirely.
[/Bar Napkin Design]

I think the above gets us started. Now, to do an "insert" we need to use the /proc/empeg_notify method of sending an insert command. Back in the day, you could do something like
echo "SERIAL #100" > /proc/empeg_notify
and it would play that FID. That no longer seems to work, and I can't figure out what the new syntax is. Anyone know if this still works or not, and if so, what the syntax is?

The other problem is that in step 4 above, if we find out we "came from" the wrong track, there's going to be a blip of some sort when we skip it. To avoid this, we would have to have the tags for song N+1 read while song N is playing. Then if song N+1 has a "PrevFID" entry and song N isn't that FID, I guess we could send a "Swap Next" command to get it out of there. In order to read song N+1's tags, we need to read the running order off the dynamic partition, which uses code I've written, but not yet integrated into emphatic.

So... In short, with some work and creativity, it seems doable... If you wanna give it a start, I won't stop you!