Glad it worked!
Long term way forward, I guess would be a new dts file - although your machine is based on the veyron design - it is different, e.g. in the installed memory. So that to me means a different dts file. That said though it would mean getting it accepted in the main kernel/device tree list.
Not sure what best way is of replacing the device tree by some kind of overlay, that really depends on how device tree is handled. What we have seen here is that depthcharge isn't doing the device tree, but that the kernel is using its own version tacked to the end of the kernel. I don't see how you could overlay that - e.g. the device tree *has* to be at the end of the kernel file, so *has* to be added there ...
Better would be for depthcharge to evovolve to do device trees, as did uboot before ...
@WarheadsSE : So the one kernel file has *many* device trees added to the file? How does chrome know which one to boot?