Regarding MQA, I would have thought an upgrade to the 861 would be eminently feasible and I will be very surprised if it doesn’t happen.

Atmos / DTS:X, if done in the 861, would surely require a complete revamp of the current processor architecture, i.e. a new model to which the 861v8 may well not be upgradable.

(Edit) So in this case I would be thinking trade-in rather than upgrade.

Main system - Sources (Kodi-HTPC, Vero 4k, FireTV, Sat) into Trinnov Altitude 32 (8-16) (+Roon), Trinnov Amplitude 8 amp & Vivid Audio (Giya G3, V1.5) and REL Stentor III speakers. Others: F80 + Raspberry Pi and other Pi systems.