your speakers looking great (*: you dont use a booster right now whats your stup?
the lg tv have a hdmi with arc function that means (audio return channel) you can use that to get audio back if you like.
But i use a -Denon-AVR-2000 receiver with a suround set from qacoustic and my tv connected as monitor
i send al audio from pc over hdmi to my receiver
and i uise the optical out from tv to my receiver for use of netflix or tv audio.
it seems my 55eg920v dont use hdr on this mom and still waiting answere lg
i hope after a firmware update.
only diff about hdmi 2.0 and 1.4 is the speed the 2.0 hdmi cable support 60hz when choosen 4k
when you want hdmi 2.0 you need to look at 1.4 high speed cable
but mos strange thing i have seen is that this tv supports 4096 by 2160 pixels whats is 4k but everybody Always talks about 3840 by 2160 pixels