What is the downside to trying?
Well I do have to apply for GE for my daughter (in addition to my wife). If I get another gold card, and charge GE fee on that card, and then find out that gold card authorized users are not eligible for global entry refund, I'd have wasted the $100. In that case, I'd be much better off if I had spent extra $75 on the additional platinum card and have the global entry fee credited to the plat card.