We’re going a bit off topic here I think, Anders.
Room correction isn’t DSP in the true sense. DSP stricto sensu is up- or downsampling, channel extraction or merging, high or low pass filters, pitch correction and such.
Room correction by software consists of volume and impulse response correction on sets of frequency ranges. I don’t subscribe to the idea that it is a good idea to do this at source level. Better to do this as close to output level as possible. Besides, in most cases a strategically placed throw rug works better than any room correction software. Hence my cleaning lady’s frustration with me, whenever I complain about furniture being moved
Anyways, I think the OP is asking about achieving the most faithful replication of a recording regardless of equipment and listening environment. Given unchanged equipment and listening environment, the best approximation of the original recording will be the one with the flattest response. In other words: no added signal processing.
I’m not saying this will be the best replication, it will just be the most faithful. A bad recording will sound bad, a good one will sound good and an excellent one will sound excellent, all within the limitations of the equipment.