> Hard mode is good enough that I'd like to see some sort of distance metric to the nearest real story, to be sure the model isn't accidentally copying truth.

Yeah, I ran into at least one example which basically regurgitated a real paper. The "fake" article was:

    Efficient organic light-emitting diodes from delayed fluorescence

    A class of metal-free organic electroluminescent molecules is designed in which both singlet and triplet excitons contribute to light emission, leading to an intrinsic fluorescence efficiency greater than 90 per cent and an external electroluminescence efficiency comparable to that achieved in high-efficiency phosphorescence-based organic light-emitting diodes.

and the real one at https://www.nature.com/articles/nature11687 has:

    Highly efficient organic light-emitting diodes from delayed fluorescence

    Here we report a class of metal-free organic electroluminescent molecules in which the energy gap between the singlet and triplet excited states is minimized by design4, thereby promoting highly efficient spin up-conversion from non-radiative triplet states to radiative singlet states while maintaining high radiative decay rates, of more than 106 decays per second. In other words, these molecules harness both singlet and triplet excitons for light emission through fluorescence decay channels, leading to an intrinsic fluorescence efficiency in excess of 90 per cent and a very high external electroluminescence efficiency, of more than 19 per cent, which is comparable to that achieved in high-efficiency phosphorescence-based OLEDs