They have left you with the problem of sorting out how to keep it below 100C with 10W is all.
That's true, I can deal with it with forced air cooling. If it approaches 100 C I will shut the test down and, provided it still works, I may keep it. Well, another test would of course be to repeat the test using a fan for cooling. All this will be done for the entertainment of all who care to read this thread.
It's pretty constant at about 38 dB attenuation so I can deal with that number just fine. It's just irritating that they put this stuff out with claims that are not being met.
I wonder if it will still fail if you are able to draw the heat away.
If I make this power meter to test up to a 10W transmitter, it wouldn't need to be keyed for more than a few seconds to check the power, or if adjusting - maybe less than a minute. I would have a fan on it and it would be OK.