Leaf swi-linux wp77xx

I am trying out leaf, but I am not having much luck.
I have set up a workspace for the wp77xx and retrieved the linux source.

When I try to build from source, I am getting errors saying that layers for the mdm9x06 are missing.
Looking at bblayers.conf I can see layers for the mdm9x28 and also for the mdm9x06.
If I have a look at the manifest.json file I can see it says MACH is an mdm9x06 and the LINUX_IMAGES and SYSROOT directories are for the mdm9x06.

Is there a bug in the manifest.json file?

I am a bit confused about few things.

In firmware release 9, 9.1, and 11, when downloading from source.sierrawireless.com yocto was always built for an mdm9x28.
When using leaf, suddenly yocto is built for an mdm9x06.
Looking at the product technical specification for the WP77XX the core is a mdm9x06 core.

Would the linux source built for an mdm9x28 be incompatible with an mdm9x06?

This is only half the problem though, as when I try to build the linux source after downloading using leaf it is missing the meta-swi-mdm9x06 layer and the build fails.