Nested VPN Tunnel / MTU Values for PC and Router?

Nested Wireguard, PPOE and only IPv4 connection.
How would you configure the MTU's on PC and Router under these circumstances?

Please help!
M -do command doesnt work for some reason so I haven't tested on my router but I tested with PC.

Testing with PC confused me however.
I'm confused because in this blog this writer says: "Since PPOE is 8 MTU, default MTU of WireGuard which is 1420, needs to be corrected to 1412"
Sooo.... How how does pinging with 1472 MTU works perfectly for me? Why should it still be 1420(or 1412 with ppoe) maximum?

And what about the router? Pc's tunnel goes inside the router's, so I would think PC should have a smaller MTU set?

I think I am dumbfounded by this. Help me out?

Much love and respect brothers.

Bump :frowning: !!!