Visual studio community in Visualstudio.extensibility in process

[gha88]

Visualstudio.extensibility primary goal is about out of process and .Net updated version.
However the in process project version still have all the access to visual studio core services.
The reason, as far as I understand is that is not fully feature. A lot of stuffs are experimental.

I'm newer to c# world and extension but some classes of this framework like the projectItem and all the cool function that hide complexity could be use.
As experiment I made some copy and paste plus some small change and it seems to be feasible.

In my opinion these will help the migration of many already existing extensions.
What do you think about?
Am I missing something about the compatibility?

Thank you all in advance