DAX Studio connects to a Power BI Desktop model using a technique that was not officially supported until a few months ago. This changed when the “diagnostic port” was documented in this article of the official documentation:
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DAX Studio uses a particular technique to identify the port used by a specific Power BI Desktop file open (the Microsoft article doesn’t explain how to related a port to a window in case there are multiple models open at the same time). However, the important part of the article is the following one.
Power BI desktop supports connecting to a diagnostics port. The diagnostic port allows for other tools to connect to and perform traces for diagnostic purposes. Making any changes to the model is not supported! Changes to the model may lead to corruption and data loss.
This means that DAX Studio will not stop working all of a sudden for a new release of Power BI Desktop – the diagnostic port is supported and we can continue to work on new features of DAX Studio without being worried that the connection will stop working one day.
The curious part of the sentence is the one written in italic. It suggests that the diagnostic port could do more than just diagnostics – even though at that point you would play a risky business, potentially breaking the model integrity in the worst case scenario.
Thus, if you want to play with forbidden unsupported activities, do your backup before – because Microsoft will not recover your broken PBIX file…