Custom values in Visma.net Project Management

[Maja Damber]

Hello

I am trying to sync projects and all their custom values from Visma.net Project Management. But I realize that the projects don't get a new LastUpdatedDateTime when changing a projects custom values. 

How am I supposed to sync the custom values without looping through all projects and getting all custom values every time? 

I thought that maybe I could get all custom values changed since last time but my only options in the API is to get the custom values for one project at a time or to ask for a certain custom value guid. And this does not seem to be the custom property guid so I can at least get all the projects values for a custom property at a time. It seems to be each value's unique guid, so one value at a time. 

This results in the need of making a lot of requests every time. How is this supposed to be handled? Does anyone have a solution?

[Maja Damber]

The same with salesStatusHistory. It seems like I need to loop through all projects everytime. I can't get only the ones that are changed since a certain date