I'm wondering if it would be possible to add another test specifically for all the "passive" heatsinks: run them inside a case? This would reduce the guesswork say, choosing between the Thermalright HR-01 and the Scythe Ninja, since if they were run in the same system/case, we could directly compare the results!
This would also take into account any mounting issues and/or weight/cantilever issues. It would also use them as they are designed to be used, whereas testing them on a bench with a fan is sorta' "artificial".
Sorry, this won't happen, generally. (Although we have done it in the past...)
This is just too tedious & time consuming. It would tell you more about how well we're optimizing the case/system for the HS. W/o mounting it on at least several different systems, you would not learn any more about compatibility than what we report in our tests now.
For example, if we chose to use a Seasonic S12-600 w/ a 120W max power draw system, with its high efficiency, high tolerance for heat and bottom mounted 120mm fan, any "passive" HS would probably work fine even w/o a case exhaust fan in one of our airflow-optimized cases. But what if it was a NeoHE430?.... too many variables to consider.
Besides, choices between HS are not about performance only -- there's all kinds of factors like...
4) config (directionality)
-- in the choice you mention, the #1 issue for me would be whether the HR01 can be configured the right way for my setup -- I personally would not try to run it passive except in a P180 (or similar where there is a hole directly above the CPU area). So I'd want the HS to be oriented so a fan could blow throught it towards the back case exhaust fan. If it can't do that, then it would not be my choice. W/ the Ninja, the fan can go on any side...
In fact, I've come to the point of view that it's mostly a disservice for SPCR to encourage fanless anything. If you are going fanless successfully w/o reliability issues, then it's because you really know what you're doing or because you haven't run it fanless long enough. (give it another year...) Fanless as a goal for most people (even in these forums) is not wise, it's not practical, it's not really "safe". A small amount of airflow from a very quiet, essentially inaudible fan can drop temperatures by 20 degrees C compared to fanless.