In general this shouldn't be possible, due to how the import mechanisms of python operate. I wonder how easy it is to break this / stale state / the usual and cause truly incomprehensible state bugs?
Yes it is very difficult, it took me one year and thousands of unit, integration, e2e tests for it to become usable. It is quite stable now although in some situations a full reload still might be needed.
Kudos for persisting through the muck and shipping.