Not sure why one would want it turned off, unless there is no control over units within the drawings/blocks one is inserting?
What blocks/drawings are being adversely affected? If it is your own content fix the units, if it's from others you wont know that until they insert incorrectly anyway,
so it is just as easy to adjust them after you know their units setting(s).
And as stated above, set it in the template. And verify INSUNITS setting is as desired as well.