Will test for a few hours to see the difference, but looks promising 540S/s against 380S/s for FOSS miner.
EDIT:
After 12 minutes one of the cards went gone...
[12836.439485] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x0013F592
[12836.439501] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A084002
[12836.439517] VM fault (0x02, vmid 5) at page 1308050, read from 'TC7' (0x54433700) (132)
[12964.285030] amdgpu 0000:03:00.0: GPU fault detected: 147 0x0c908402
[12964.285047] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x0013F592
[12964.285063] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A084002
[12964.285080] VM fault (0x02, vmid 5) at page 1308050, read from 'TC7' (0x54433700) (132)
[12976.758284] amdgpu 0000:03:00.0: GPU fault detected: 147 0x00004802
[12976.758303] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x00200000
[12976.758320] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A048002
[12976.758337] VM fault (0x02, vmid 5) at page 2097152, read from 'TC4' (0x54433400) (72)
[12976.766850] amdgpu 0000:03:00.0: GPU fault detected: 147 0x0c908402
[12976.766869] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x0013F592
[12976.766885] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A084002
[12976.766901] VM fault (0x02, vmid 5) at page 1308050, read from 'TC7' (0x54433700) (132)
[13065.948618] amdgpu 0000:03:00.0: GPU fault detected: 147 0x0c908402
[13065.949169] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x0013F592
[13065.949713] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A084002
[13065.950283] VM fault (0x02, vmid 5) at page 1308050, read from 'TC7' (0x54433700) (132)
[13461.645347] amdgpu 0000:03:00.0: GPU fault detected: 147 0x0c908402
[13461.645898] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x0013F592
[13461.646437] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A084002
[13461.646977] VM fault (0x02, vmid 5) at page 1308050, read from 'TC7' (0x54433700) (132)
[13474.869840] amdgpu 0000:03:00.0: GPU fault detected: 147 0x0c908402
[13474.870393] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x0013F592
[13474.870931] amdgpu 0000:03:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0A084002
[13474.871471] VM fault (0x02, vmid 5) at page 1308050, read from 'TC7' (0x54433700) (132)
Still issues with this miner.