Lumen Output (Eco Lamp, Dynamic): 1176
The drop to Eco mode of the W1080ST projector results in a loss of 35% of the lumens, a number almost identical to the W1070's measurement.
Smart Eco mode can't be measured that easily, because it depends on what the image is. At its lowest with working content, it should be about the same as Eco mode, but on bright scenes it will be about the same as full power. Per BenQ, when there's nothing going on, it can drop 70%.
Check it out. First is Normal (full power) then Smart Eco, then Economic: