Currently, all COGO distances are stored in the units of the parcel fabric's projection. That's a good thing, and I don't suggest changing that.
However, there are plenty of boundaries that are defined as having different length units. I can use things like chains, rods, yards, and meters to enter my lines via the Traverse tool, but I have no way of retaining that kind of information.
On parcel features, there is a "Stated Area Unit" field, which is great, as some parcels are defined in terms of acres, and some in square feet. Reflecting the legal area as recorded in the associated document.
What I'd like is the same thing, but for line features. Then I could show that "this line's distance is measured in chains / rods / whatever".
Bonus points if an attribute rule could automatically populate the COGO field with the default unit equivalent multiplied out, but that's not strictly necessary.