....Just trying to be sure I understand, is it that you see RVX as essentially finished, from a shareholder's view?....

No.  I didn't say that.  It just doesn't make any sense to combine the two.  That desire comes from fearful RVX shareholders IMO. 

RVX has significant risk.  As a shareholder of ZEN but not RVX, it would be a negative for me.  I already have an "option" (royalty shares) on the success of RVX.

RVX and ZEN have separate products, separate IP as Sarah just mentioned.  It's easier to sell them separately. The timing for a buyout of RVX vs ZEN is different.

Any company wishing to do a buyout is less likely to be interested in both.  If they want both, they can buy both.