I haven't tried a USB adapter with proxmox, but there's a chance it would work. I was also looking at a cheap pcie card like this one as a way to add another ethernet port. https://pcpartpicker.com/product/dQmLrH/tp-link-wired-network-card-tg3468
That being said, the steps in the link that David gave have worked for me to stop the hardware hang issue with the intel nic. Basically disable tcp segmentation offload and generic segmentation offload with ethtool -K eno1 tso off gso off. You can add a post-up command to the interace config to make it persistent.
I've been using ATAC (Arguably a Terminal API Client) lately because I like everything to match my terminal theme.
https://github.com/Julien-cpsn/ATAC