The IDO2 findings are the strongest suggestion that something could be going on with regards to the metabolic trap theory. Strictly speaking though, it's still more at a hypothesis stage than a theory. I have some doubts with regards to how the hypothesis fits with observed "temporary remissions", which is the thing I have been curious about the last few years. The perhaps most common temporary remission and one that Ron Davis spoke about as well is improvement during an acute infection, in my case, full recovery more or less.
The metabolic trap could perhaps be somehow temporarily circumvented during a cold through regulation and changes in IDO and kynurenine, which would make sense to me. But what I find harder to understand is this: since it is possible to reach a temporary remission, why does the sick "state" return back quickly after the cold, in a matter of a day or two? According to simulations, the metabolic trap requires a stressor and quite a bit of time as well for the tryptophan levels to rise enough for the trap to be sprung. If a cold takes you out of the trap, shouldn't it be possible or even likely to achieve a permanent recovery or at least not get back with ME/CFS symptoms right away.