Thanks for the reply - are your teams working with Microsoft API folks to get this added or is this the end of it? With the roll out of PMAX on Microsoft Ads Troas is really a key data point for performance management (there aren’t a lot for PMAX, but campaign level budget and Troas are a must have)
Typically data source source functionality is introduced to the UI first, and follows via the API later. API functionality is entirely determined by the data source themselves, and as such we are unable to advise if/when Microsoft Ads will add support for Campaign level Target ROAS.