Sadly, no form of coconut milk leaves a fragrance behind in the soap...even when it smells yummy at the batter stage. I am always searching for a lovely, true to life coconut FO and I have yet to find the right one for me.
I do the same, reserving some liquid and mixing the powder with that, then adding at trace. I have found that if you add too much coconut powder it can make the soap crumbly.