Having dealt with same problems for years now (we call our UDM - Unified Data Model, heh), I was under the impression this was an over-engineered Datamart++; It's not though. Calling UDA a datamart would be like calling K8S a bash script, which might be related but wildly different in scope.
I am definitely interested to read more and implement it myself as well. Would also be more than happy to skip the whole GraphQL end of it.