So light and sound intensity are continuous scales. They also are physics but taste and smell are chemicals. Chemistry, molecule properties are a discrete scale. Now you make a distinction between food chemicals and non-food but that distinction is already based empiracally on “what tastes good and does no harm” so a poor choice for this answer.

Indeed, no but demand is rising as osm becomes known and a legit map replacement.

When traffic’ll pop it will be a pluggin in osmand I believe :)

As it should be, I’ll reference the openTraffic effort wich I think is stale since about 10years. There definitely is a need for this infrastructure as opensource map users grow along the years. https://github.com/opentraffic