Yes most movies are 48k, but lots of Bluray audio discs have 96k and above DTS-HD soundtracks.

My HD621 is a HDMI endpoint in Roon. It sends multichannel PCM96K to G65 via MMHR connection.

Main system:G65, 218, HD621 2 x DSP5200SE, 1 x DSP5200HCSE, 2 x DSP5200SL, Power Sound Audio S1512, DSP Anti-Mode 2.0 Dual core, NuPrime H16AES, 518, Dune HD Homatics Box R 4K Plus running CoreElec 21.3, Oppo 103D and SqueezeTouch. Atmos, MQA and Trifield! smile