kernel config files outside of sys/${ARCH}/conf ?

usr/sbin/config assumes that the kernel config file
lives in ${src_base}/sys/${arch}/conf , which means that
if you need to build a custom kernel one needs RW
access to that directory.

Any idea on how we can enable config to work in a
generic directory ?

I scanned the source code usr.sbin/config and found that
it uses hardwired paths -- specifically, it looks for
the kernel source tree in "../.." and has multiple
hardwired paths such as "../../conf/".
There is also a somewhat undocumented access to a
file called DEFAULTS that extends the configuration you pass.

Any objections to the addition of a "-s" option to config(8)
to specify the location of the source tree ?

cheers
luigi