Peter, I just switched from multimode to the Lumin-recommended Corning single-mode fibre and Finisar transceivers. There is, indeed, an uptick in micro details.
A question: Robert Harley observed in his September 2022 review of the P1 in “The Absolute Sound” that Lumin said the fibre input would take a long time—many hundreds of hours—to break in and sound the best. Do you know whether this is a reference only to the physical Lumin input or the combination of the input and the associated SFP modules plus fibre?