I read your excitement about the latest Topping and Allo products, both of which I did not get a chance to get my hands on yet.
The relation between AP jitter measurements and their audibility at the output of a DAC still puzzles me, as I have the impression that not all variables at work (jitter distribution) and distorsion mechanisms are fully understood as the DAC chip manufacturers like to pretend for quite a few years now. The associated filtering certainly impacts the perceived result. I simply do not find that Benchmark DACs sound as good as they should given the published measuments. I am not a fan of euphonic effects (like 2nd order harmonic distorsion in some amps) but a clean sounding DAC doesn't necessarily translate for me into musical enjoyment and connectedness with a recorded venue or a synthetized artwork.
With Steves latest enhancements (have you actually tried these with his reference coax cable?) the SychroMesh is quite good with wall wart, but I still find the result to sound somehow sterile and constrained in my setups, although the SM measures well. For me the magic really starts to operate when a Dynamo or a stock Paul Hynes power supply (latest "turbo" version) is connected. I am pretty sure the standard AP jitter measurements are not very different although I cannot prove this assertion, but there is definitely something going on with these power supplies that triggers my attention and drags me fully into the music. I use an older NOS DAC and tried a Sabre DAC (3 years old) in my secondary system, and both benefit of reclocking. Maybe the AK chip in the latest Topping finally implements a way to push incoming jitter related issues into the inaudible realm. I would be happy to hear that for myself!
For me, an SPDIF reclocker is especially useful when you cannot use a USB connection, as for example from a TV set top box, a smart TV, a CD, DVD or BD player, etc. In my main rig, I connect an SM reclocker to a DLCP DSP+6 channels DAC from Hypex (Ncore amped LXmini+2 active loudspeaker system) and the result is nothing short of exceptional. Last time I secretely removed the reclocker my wife asked me the next day if something had changed as she was not feeling the groove and ambiance that she appreciated so much anymore (note that she is basically streaming compressed music from Spotify and watching TV).