Just testing non-desktop software on ARM – you could use a Raspberry Pi 4 for that. Or a Pinebook Pro. Or just an EC2 instance!
For "real workstation" class hardware (i.e. working PCIe/XHCI/AHCI on standard ACPI+UEFI systems with mostly FOSS firmware) nothing beats SolidRun boards (MACCHIATObin/HoneyComb LX2K). Yeah yeah the Cortex-A72 cores are really showing their age, oh well, on the other hand the SoCs are not embedded cursed crap :)