`using` vs `include`

[eelstork]

Dependency management does not live up to how dependencies actually want to work.
include style dependencies are okay if we have a relatively concise interface between the BT and C#

In practice C# needs to expose ad-hoc properties which often have strong cohesion with just a subtree or task.

using dependencies are the way to go, and there may be a need for local (function level) variants.