Every distribution has a slightly different variation of install location, which is not good - we can't tell end users that "this is the place you can expect to find your device tree files regardless of what distribution you choose". Some questions I have here before we proceed discussing what would be the standardized location:
1) Anything missing of the pros and cons of different locations?
2) Are you interested in moving to a standardized location if cross-distro list proposes one?
Feel free to either comment here and/or update the wiki.
Riku