The Brume is my ideal home edge router. I use it to pppoe to my ISP (rather than using their provided modem), and control everything my way with a full linux rather than annoying OpenWRT. Decent IPv6, finally.
By far the most important improvement for me would be an up-to-date, maintained Linux distro, I don’t care if Ubuntu or anything else, with a more recent kernel. Upgrading the gl-provided OS release isn’t that hard (though troublesome), but getting a recent kernel in there with a modern Wireguard is too much work.
It also would benefit a lot from not having the pcie slot removed, I would totally make it into a mini NAS with one. I feel like the Brume is underrated as a microserver, it can handle a lot.