Performance Issue for 170k nodes with different node types? How to load the values?

Summary:

There is a hierarchy for the EPBCS application in EDMCS wherein we are expecting 170k nodes. We have 3 node types present in the hierarchy because the purpose is different for each - Parent ITN, Child ITN and Project (Project is the dimension node type).

Is there a way to load the 150k Projects into the viewpoint using Viewpoint Load? Viewpoint Load does have a limitation and using Import method will not work because it will import all nodes (including Parent ITN and Child ITN) as the "Project" node type which is not what is required.

What will be the best possible way to go about it? Also, on a side-note - faced performance issues in EDMCS to load 15k Parent ITN and Child ITN through viewpoint load. There will be around 30 attributes for these nodes.