Cellular MTU experiences

I have two tunnels over satellite and cellular and am wondering what experiences are with cellular mtu.

I had setup the wireguard over each with the default 1420mtu, but was my experience on cellular was not optimal. I found some commercial lte wan documentation that suggests cellular mtu is 1420, so after setting wireguard mtu to 1340 performance is improved. Since i fail between both, the tunnel for satellite also needs to be 1420.

Is this generally the best performance over cellular? Are there any experiences with slightly higher mtu and LTE?