can you run HDMI to 4KTV and optical to receiver.
unless you have a 10k + speaker set up, purpose built room with acoustic treatment and perfect hearing you are not going to notice lack of lossless audio
This post should come with a trigger warning :)
I can notice differences (sometimes). Generally, find the bass more punchy and audio generally more dynamic, you can hear little details like when a guitar is picked, the initial sound hits more clearly and the decay is more clear. That said, for music listening I tend to use headphones these days.
So much depends on having well produced material.