The stock firmware of the Beryl AX does not support connecting to WPA2-Enterprise Wi-Fi. You’ll need to use the OpenWRT 24 firmware instead. For detailed instructions, please refer to: Connect to EAP network - GL.iNet Router Docs 4
The USB power supply of the Brume 2 and Beryl AX is limited, so if you plan to use other portable HDDs without their own power supply in the future, you may need to use a USB hub with external power support.
Your plan actually makes sense for the speeds you mentioned. Since your home connection is only ~60/16 Mbps, buying very high-end hardware won’t give you much real benefit for the WireGuard exit node, because the upload speed (16 Mbps) will be the main bottleneck when you connect back home. The Beryl AX is a solid choice for travel. It supports Wi-Fi 6 and WPA2-Enterprise, and it should handle WireGuard and SMB sharing from the USB drive without issues at your current internet speeds.
For the home setup, Brume 2 is also reasonable as a small VPN gateway connected to your ISP router. It’s efficient for WireGuard exit node usage and should easily handle your connection speed.
So overall your ~€100 setup (Beryl AX + Brume 2) is practical and cost-effective. Upgrading to newer Wi-Fi 7 travel routers wouldn’t really improve performance unless your home internet speed increases significantly.