Thanks Mochi!!!
I add mushrooms to all of my stir fries for their anti-cancer properties. I'm not sure, would the mushroom powder add a different flavor. The Indonesian sweet soy sauce sounds good. But I normally add some type of sweet in my stir fry, like I blend apricots or apricot jam with my soy sauce and that makes it sweet. I usually add something hot too, either red pepper flakes or sirachi sauce or something similar.