At this moment customer have three environments available by purchasing licences for D365FO. And this is not enought based on standard funcionality that customed should have. Here is why... When customers start their implementation project, they have three environments available. Later in project FastTrack recommends to have T1 configured as BUILD. Other is for testing and gold configuration and last as PROD. But when project goes further in implementation there is need to debbuging. Always will be when there is ISV development. But now, MS recommend or ever wants to have this environment as Microsoft-managed. This mean to customer pay for another T1 as standard funcionality of D365FO as a system. This is because accessing SANDBOX with refreshed DB from PROD. These are standard functions. This should have customers in basic configuration, if it is not possible to debug from cloud-hosted environment. I suggest to Microsoft to consider about giving customers another T1 for debugging in basic licenced project. Not as T1 Add-on. BUILD and DEBUG are basics, so why customers need to pay addon for it. At this moment is T1 for nothing because it should have been BUILD. Or create build funcionality as service on LCS.