Okay, I talked to Maiden666 who did some really good tests on the Imalent DX80.
According to him, the DX80 can be turned on in Med-Hi mode for 6,000 lumen in a 25°C/77°F room with no fan and it will maintain that output until the batteries drain. This beats the Acebeam X65 that does 5,300 lumen under the same circumstances.
If we add a fan to circulate air around the DX80, it can maintain 7,000 lumen. You have to first turn it on at a higher level and then let it step down, though.
If we look at his chart, we can see that both Turbo and Hi will step down to 7,000 lumen. Turbo will maintain 7,000 with no fan for about 17 minutes then the temperature hits 65°C/149°F and Maiden666 turned on the fan. From Hi it lasted about 32 minutes before he turned on the fan. (the red and green triangles in the chart is where he turned on the fan)
I’m not sure what would happen if he had not turned on the fan. Maybe output would have dropped to 6,000 lumen?