From what I have been able to gather, the advantage of the cyanide system is that it will greatly reduce the amount of extraneous material and the volume of material that needs to be smelted. The cyanide system product is pretty much all metal, since it is an electrolytic product, so smelting then is pretty much melting it in to bars. I think the cyanide system won't change the recovery of gold much if the flotation system is indeed getting out 90% (and indeed, the flotation product is what will be put through the cyanide system, so anything the flotation system left behind won't be processed anyway). The cyanide system should also get out more silver that can't be recovered by simple smelting without added flux.

So the calculations don't change much. Some more silver recovered (that otherwise might end up in the slag and have to be sent out or saved for later recovery). More expense to run the cyanide system, but less volume of material to smelt. Smelting is pretty energy intensive, so maybe some savings there.

Again, this analysis is based on my best take on how the system will work. Not necessarily 100% accurate, but I think I'm close.