I'm assuming this would need to be a Module on which others (pedestal or ring) would depend. Arachne's DSL is a friendlier way of transacting to the static Config Value on which the Runtime is built. i.e. it's friendlier than writing datomic-style transactions expression by hand. If possible, we want to get everything that can be represented as data into that initial config value before building a dynamic runtime on top of it.
For these reasons, I'll go out on a limb and say: Yes, you probably want to write some config DSL as part of your Arachne Module authorship process. I've yet to write my first Module so I wish I could be more help. Please let us know how it goes.