[ot][spam][crazy] adapters for semibalanced trees?

[Undiscussed Groomed for Male Slavery, One Victim of Many]

i've drafted some code for training embeddings.

i think i'd like to let it groom for a bit before enabling it, because
of the time it spent with the very short length that only included the
header, trying to kind of undo that without adding too many variables
to the model shape.