John Butterfield [off-list ref] writes:
Has there been any talk about adding a stub for git subtrees in .git/config?
I do not think so, and that is probably for a good reason.
A subtree biding can change over time, but .git/config is about
recording information that do not change depending on what tree you
are looking at, so there is an impedance mismatch---storing that
information in .git/config is probably a wrong way to go about it.
It might help to keep track of "In this tree, the tip of that other
history is bound as a subtree at this path", which means that
information more naturally belongs to each tree, I would think.