Just to be perfectly clear and not leave any ambiguities: WiiM devices do not support eARC but just ARC.The eARC works great for stereo - this monitor has smart TV apps built in so by using eARC, I don't have to change inputs if I use the built in apps (my wife and I watch TV in my offices when they kids are playing on the living room TV)
In theory, Battlefield should be able to send Dolby Digital without an encoder but I'm not sure exactly how it works.
8 channel PCM is clearly not possible.
I miss my old surround setup and have been thinking about going to a Marantz Cinema 70s...
Fittingly, the only multi-channel format supported is Dolby Digital (AC3). No Dolby Digital+, no Atmos, no nothing.