Share your thoughts on DirectQuery for Power BI datasets and Azure Analysis Services (preview)

So far, I have really enjoyed this feature, connecting two PBI datasets and creating simple visuals, measures and calculated columns just seems to work, though perhaps a bit of a memory hog. However, now I have a scenario whereby I want to append one table from one source onto a table from another source. Curious whether this can be done with Composite Models, I tried creating a calculated table but some of the DAX table functions are throwing "unexpected exceptions" is this a Direct Query limitation? I couldn't seem to find the answer... 

*Edit* Nevermind. Found the answer. It's not supported.  🙂