They made an Ethernet board, I don't think a buck converter would be hard for them, but, as they said, it does increase the cost.

Honestly, hooking up a simple Ethernet switch IC is a cool project but isn’t especially difficult - and this is only 100 Mbps also so not very tight tolerances.

Set up your design rules right and I’ve had gigabit RGMII and 1000Base-X work first try.

For sure, this wasn't that hard. But I think that's great; it means anybody can be an EE. That's a core mission of our team. Our team works hard on PCIe 4.0, USB 3.1 Gen 1, and Gigabit ethernet as well. This is just one board that we made and were proud of. Feel free to take a look at our other boards in the documentation website!

how hard do you find pcie v4? did you look at how big a step is it to v5?

Yes, if you're an expert at designing PCBs, I'm sure it's not hard. It's objectively hard, though.