Yes, because babanuki said that the power of the handcuffs was enough to allow anyone using them to just have the strength to walk around, haki consumes vital energy, luffy couldn't use haki because of that, not because the handcuffs prevent haki from being used, but because they generate enough wear and tear for luffy not to have the strength to use. It's exactly the same with water, luffy in arlong park was submerged and only had the strength to use his powers with help because at that time he was weak, but in fishman island and he had enough strength to use the fruit and haki even with the pressure of water on him.
That's my vision of the thing, Yamato as able to use Haki with handcuffs but not his fruit.