Override at Footprint Level

We'd like the ability to override the rules at the footprint level.  For example, on QFN's, we prefer the round hollow circle on the assembly layer that correlates with the recessed circle in the package for polarity to make it easier on the SMT assembly house to identify.  But when the QFN gets small (~4mm square), we don't have room for a hollow circle and would prefer to use a corner chamfer in those cases.  

By default, we do not include polarity indicators on assembly outline since we use a hollow circle for 95% if cases.  In the case I have a small body part where the circle becomes too ambiguous to define a corner, if I go into the part in my FPX library, go to Drafting -> Assembly and check "Include Polarity Indicators" and then click OK, it adds the chamfer to the assembly outline.  I then Add to Lib to update my existing part.  If I view another part and then go back to that part, the assembly outline is no longer chamfered.  It allows it to be done but does not seem to save that unique setting on a per part basis even though what I wanted was correct in the Editor window.