Welcome don’t get too concerned about run in, just enjoy your music but leaving the radio playing 24/7 through the speakers even at low volumes will help.
Received the NDX2 over a month back and although I knew it had to be run in I most did that whle listening. Only additional thing is that I left the music playing while I left the house or went to sleep, albeit at lower volumes
As for the SN3, I believe unless it is sending current to the speakers then the “silent” run in is partial.