At last I found a RIGHT way of reversing stereo channels for #pipewire!

1. Find an id of your device with `wpctl status`

2. Get node.name with `wpctl inspect ID`

3. Create match rule:

cat > ~/.config/wireplumber/main.lua.d/51-swap-channels.lua << EOF
rule = {
matches = {
{
{ "node.name", "matches", "node_name_from_step_2" },
},
},
apply_properties = {
["audio.position"] = "FR,FL",
},
}
table.insert(alsa_monitor.rules, rule)
EOF

4. Restart wireplumber

Thanks to ArchLinux forum: bbs.archlinux.org/viewtopic.ph
All the other properties could be changed there as well