Injector oil for 2007 Optimax ProXs 225

Hi guys, wondering what injector oil to use in my 2007 Mercury ProXs 225? It looks like OptiMax/DFI or Quicksilver was recommended some years back, is that still the current Mercury choice? And is there any danger mixing synthetic with whatever is currently in the tank?? Thanks in advance!

I use the Opti/DFI oil although the standard Premium Plus is just fine and much less cost. No problem mixing it with existing 2 cycle oil in tank.