Why say umami? I think we have adequate english words, like hearty, that means exactly the same.
It was synthesized by some japanese a long time ago out of seaweed. The reason sushi actually tastes like something is the seaweed enhancing the rice/raw fish taste.
Consuming large amounts is said to damage "cells", in south China for example, people eat lots of fish soups that consist of MSG by the spoonful, a bit of fish and some chives.
Statistically, people wear a lot more glasses then in the north. There people eat hearty foods, bread, meat and noodles in broth.
So why do you get the chinese restaurant syndrome? Overdose! If you eat cup noddles every day, ur used to it, like coffee, a couple of beers...
On bbq, a bit rounds out the flavor, but if I would cook vegetarian, I'd use a lot more. Or substitute with seaweed.
Weber 22.5 OT-silver with cast iron grate
Kamado for low and slow, and baking.
Smokey joe for trips.