Makes sense. I wouldn't consider it for 2.x though.
The issue Jason refers to is the fact that tce-load currently exits if a dep doesn't exist.
If in 3.x it would instead just skip it, while still of course printing an error and exiting with an error code, having a variable would not cause issues to those having modules in a differing form from the repo.
Also, I'll likely post the sorting script for the 3.x series, so that should help with creating the extensions.
On the other side, do you mean to post the extensions to the standard repo? I see the issue that having them there would cause confusion, and expectation that we offer officially all the kernels for which there are extensions.