Yes. The main premise for use in an Meridian System is to avoid the HD621 altogether (and the HDMI run to it).

I use a VanityLite (no longer available) to connect my Oppo 103 to my 861v.4. I also run my DirecTV box to the Oppo HDMI input, then out the vanity mod SPDIF to the processor.

James
NC1: 861v8, ID41, 218, 251(to outdoors), DSP8000SEUG, 7200SEC, DSP520 rears, Apple TV, DirecTV, Oppo BD103, QNAP251, Roon
NC2-M7005, Triad Silver Speakers,Acurus Amps

FL1: 861v4, ID40, 218, MS200, DSP8000SEs, DSP7200SEC, DSP5000s, DirecTv, AppleTv, OppoBD103, QNAP469, Roon
FL2: Marantz 7005, 251, M60s,60C,33s, Oppo BDP-93,MS200, Roon