How to disable the automatic inline hierarchy???

Not exactly sure how you've written your measure.  There are lots of ways to author these kinds of measures.  However, the point is that a simple aggregate (e.g., SUM, AVG, etc.) with no Calculate or other mucking with the filter context will automatically filter the data to be at the leaf level of the hierarchy.  So, say a measure of Average NPS (Net Promoter Score) that is calculated as you go down a hierarchy (Say Region and then Product) will absolutely work correctly.  At a leaf level (Say Washington State and then Product A) the data will be filtered to WA and then Product A and the aggregate (Avg) will aggregate over that data.  When you move up to just Region you would be able to see the Avg NPS for WA. 

All that said, we are finally very very close to publishing an update that will give the old button the old behavior and a separate new button that will enable the new behavior.  As Alex mentioned on a different response, there were some issues in terms of how these features worked with other parts of the product that we had to work through.  That is all done now and we've begun the update process.  Again, I don't want to give a specific day (since delays seem to inevitably happen) but process wise now it's a matter of getting it posted and aligned with the service.