I use natural almond milk without additives. This is fantastic in cold drinks.
However, in hot drinks, such as hot cocoa, it feels flat.
I have investigated corn starch, and have heard of xanthum gum and guar gum. What could be used for hot liquids and almond milk. Corn starch does not seem to affect mouth feel much. I believe the fat content of my natural almond milk s/b pretty good (perhaps 6g per 8oz)
Toasted almond flour.
I hear what you are saying about the almond milk. It lacks depth in a way that is hard to describe or maybe has a flat taste that like many off tastes are easier to perceive when hot.
I propose with no evidence at all that you could add a little toasted fine ground almond or almond flour. This is not some exotic stranger like xanthan gum, just more almondy goodness. Thickening stuff with flour of any sort is totally legit. Toasted almond flour is very nice for breading or things of that sort.
You would need to keep stirring it up I think.
My overall experience with plant milk in general is that it falls "flat" mainly due to lower protein content than regular milk and lower saturated fat content.
I don't know the source of the figures you stated in your question, as your average almond milk contains 2.5g of fat / 240g of milk, which is equivalent of 1% fat, and all of that fat is unsaturated. For comparison, whole milk is 3.5% fat, and ca. 60% of that fat is saturated.
That is one of the things that make the mouthfeel of hot cocoa, along with the thickness
For hot cocoa in particular, I recommend using actual chocolate bars / chips / chunks instead of cocoa powder to amp up fat content a bit and thickening with your thickening agent of choice - I use cornstarch as it is easier to procure where I live.
