well, after many, many coats of conformal coating, I don't think it made much difference. I have attatched a frequency graph before and after, but you can't really tell which is which.
It looks like it did damp a 9khz subharmonic, but not the massive spike at 18khz.
out of curiousity, I passed a single loop of wire through the transformer and connected a scope to get an idea of the signal passing through that transformer. looks to me like an 18khz square wave with varying duty cycle to approximate a sine wave, which i guess gets smoothed out by the inductor above and some caps that follow before the output, which I suppose is about how i figured it worked. given the lack of a big chunky 60hz transformer, it appears to be using the equivalent of a class D amplifier to drive a transformer. with the output being filtered to remove most of the 18khz ripple.
If only this thing would go into eco(bypass) mode. from what I can tell by heat, most of the energy is lost in this transformer and the associated inductor, so they are definitely switching that part of the circuit off in eco mode, sadly even tripp-lite support couldn't figure out how to enable eco mode, as my unit just ignores the command from their software.
maybe my next thing to try is silicone. I don't think I should totally pot the thing due to it already running around 150F under full load, but maybe smearing it into the gaps between the windings and core will help without causing it to heat up much more.