Workaround - for alternate units in 2017 deluxe. Create a new dimension style.
View menu or maybe Tools menu - palettes - style manager (depends on ones workspace configuration). in the style manager expand dimension, click standard (you can alter standard but personally I'd leave it as default), click the top icon - create new style, and set it up as required with alternate units of choice, ensure rounding, precision and Multiplier are set correctly, or you can get some odd figures. The new style will be available at the bottom of the dimension properties page. If you right click the dimension icon and set the style before adding the dimension, the new style will be the default for further dimensions in that drawing. NOTE you will not be able to alter them in the properties dialog but one can alter things in the style manager. The style manager affects everything using that style, hence why I suggest keeping standard, for dimensions which you don't wish to have appended units.
These styles are drawing specific, so unless you create a template with everything set up, you would need to create a new style whenever you start a new drawing. I don't have 2015 deluxe so I've no idea what was in there.
The above was tested in 2017 deluxe, and hopefully it will work for others.