I notice a lot of see-sawing on Config.lb files.
Please consider having multiple Config files for a given target. So, for example, you could have
arima/hdama/Config.etherboot.lb arima/hdama/Config.kernel.lb
and so on. Each Config tool should build to a different target directory, to make multiple concurrent builds easy.
The the buildtarget tool can default to <target>/Config.lb, but a user can also specify (in future) <target>/<some-config>
ron