Originally Linux’es kconfig machinery we used to (almost) exclusively collect choices of which features/components to build. This is also what we’ve originally inherited when cloning kconfig for Xen. Meanwhile Linux has moved to collecting e.g. tool chain properties there as well. Some Xen maintainers have pressured for us doing the same, and we’ve already gained a few instances of such. However, before generally going that route I think upsides and downsides need to be weighed; there’s no reason for us to blindly follow what Linux does.
Once an informed decision has been made, full conversion in the decided direction should be carried out.