right now, we are directly managing git checkouts but bb has fetcher code to do this and alot more which it would be a good idea to use. This becomes more important as we look at adding non git layer sources.
Moving this to 'Medium". Although this is an important enhancement, the "Medium+" status is tracked in special ways even though this is set to "Future".
We're working on a layerindex download manager as part of bitbake. This would allow the toaster to use a unified interface to download layers either from the index or from a direct URL specified by the user.
Mark Hatle's work on a layerindex download manager as part of bitbake is currently on hold. I will continue to track this.