REST API /rest/api/3/filter?overrideSharePermissions=true does not handle project roles?

[KC Wong]

How experimental is the overrideSharePermissions query parameter?

I gave it this edit permission: 

"editPermissions" : [ { "type" : "project", "project" : { "id" : "10027" }, "role" : { "id" : "10002" } }, { "type" : "project", "project" : { "id" : "10027" }, "role" : { "id" : "10016" } } ]

And it ended up only shared to the project (Everyone) instead of the two specific roles I've given.

If I use the UI to edit, then I can share to those two role ids. 

Is role assignment not implemented in the REST API yet? 

[KC Wong · Accepted solution]

Never mind... it wants the type to be "projectRole" on create/update.

But when reading, it will only give you "project" type with both project and role children.