Will clock upgrade improve HDMI output

I am close to upgrading the masterclock on my Denon 2500 trransport (which has HDMI output only), but now have been told that since HDMI is an asynchronous standard, this will not give any improvement (I am interested in the audio quality only). Could anyone tell me if this is indeed hte case. I can still abandon the upgrade, but need to decide very shortly, because the player is on its way to the modder!
What does the modder say?
Touch'e Cruz
Obviously he says it will improve the signal/sound. I have no doubt to question his integrity (I asked Dan @ MOdwright about the clock and he suggested upgrading the clock would probably improve digital out over HDMI as well). However, I don't think the modder (nor Dan) has ever done this for an HDMI only transport, and may simply not know. I do know that everyone that has proprietary solutions (HATS, DenonLink, Meridian etc.) turns the source into slave and sink into master, so the source clock does not matter, which would support the argument upgrading the source clock over HDMI is a waste of money.
I reread my message and I said "I have no doubt to question his integrity". This could be miscontrued as suggesting I am questioning his integrity (slip of the keyboard). What I meant is I do NOT question his integrity.