There have been some changes made to the add-in in the 2020 edition that should be taken into consideration.

CSOM Support Discontinued

Prior to the 2020 edition of the add-in, connections to Microsoft Project using both the CSOM and OData interface were supported, which lead to difficulties in maintaining the two schemas concurrently.

By removing support for the CSOM, connections to Microsoft Project are streamlined due to the lack of special connection properties made specifically for each schema. Also, the OData interface can now perform all of the same CRUD operations that the CSOM is capable of. Lastly, the CSOM is poorly documented and more error-prone than OData.

For these reasons, the decision was made to deprecate support for the CSOM in favor of exclusively supporting the OData interface.