Hi Oliver,
Although you did answer the question about whether or not IRs were used, you went too far in saying that "IR is clearly the opposite of physical modelling."
As a counter-example to this claim, it is entirely possible to write a plate reverb plugin that solves the PDEs to create IRs in real-time, IRs that are used immediately thereafter in the same plugin. I've written programs that do this kind of thing. Although there is a spike in CPU usage whenever the IRs are recalculated, once an IR is obtained there can be less CPU usage. Of course, an IR needs to exist for the system, and many systems of interest do not meet this requirement.
I do agree that usually people measure IRs and that this would not be physical modelling. My point is that there is more than one way to create an IR, so again your claim goes too far.
Regards,
Dave Clark