Was pretty cagey (obviously), but pretty proud/happy.
I asked if it was an ester, and he smiled, said he couldn't say but it wasn't far off.
Stated also that their test regime (no details, other than it was an engine test) used a reference oil (M1 5W50 no less), a flushing oil, the test oil, flush oil, and then reference again to bookend the testing.
Said that the residual surface agent was evident in the second flush, and on into the reference oil second run as well.