This is a cool API, and I'd like to use it (from the server api).
Unfortunately, I can't. It lacks access to UserInternalData. I would also need TitleInternalData... but I'm more likely to be at peace with being unable to get title data through an API designed for getting user data.
Also, as discussed on slack:
GetPlayerCombinedInfoRequestParams has parameters like "GetUserInventory" (required) which "defaults to false". Since it's not optional, there's no default