This thread first discussed, if "the score" can be trusted. You added an interesting aspect. Reflections have to be considered as detrimental for the sound stage realism. The score doesn't take the width of the dispersion pattern into consideration. If I get You right, the score doesn't tell it all, hence shall not be taken as a final verdict.
You reintroduce the argument with mentioning the room affecting time domain, decay and tonal balance--the main concern of the score, conclusively. You then advertise a closer listening position, which naturally would mute the reflections relatively.
This is a side-move, me thinks. I don't want to analyse its persuasive strength. I would rather like to come back to Your sound-stage argument. This could be valid, indeed. The score relies on mono listening tests, and there should be doubt if it was applicable for stereo in the first place!
I lately expressed my expectation, that reverberation in contemporary recordings is either recorded separately, or is generated synthetically, and in either case added to close-proximity, individual recordings of the solo instruments. Other, additional techniques might apply.
Now, if the reverberation isn't stereo in itself? The reverberation, as said recorded separately or synthesised, is basically mono, added without further ado to both stereo channels without differentiation. What then about the time relation of in-room reflections to the direct sound? And by which means would these affect the plausibility of the stereo imaging?
I personally argue, that reverberation, by our all hearing, isn't evaluated for directional cues. Experiment: close an ear and try, blindfolded, to orient Yourself confined in a room. Possible - proven! The notorious two-ear technology isn't needed to get the picture. Maybe it is just the significant burst of the early and late arrivals, a timely, but not directional pattern of reflections, that portrays the room.