The soapy taste might have came off from the can's metal? Often time, I find many can food have this coppery/irony/lead taste to them. So, if using fresh coconut milk, I would suspect eliminates the soapy taste that you often get from the can stuff. I've never tasted that soapy taste you describe you had before. I only make Thai Curry, which is loaded with lots of spices and chilies, so you can't taste any soapy taste either when using can coconut milk.
Here they market two different products of coconut liquid, coconut cream is thicker, richer, creamier tasting and has more oil content, coconut milk is thinner, more liquidy/watery and less creamy/rich tasting.
I really don't know if they use corn flour/starch to thicken the coconut milk, but it's possible.
Would love to try a fully germinated coconut, but only way is if I was in South Florida or other tropical places that coconut can grow well. At regular stores, we can usually find either brown husk mature nuts with water or young nut with water and young flesh, no germinated nuts to purchase.