3rd attempt at mounting to reduce temps, ready for the new fans. This seems to be the approach most are taking, flat with a 1" gap underneath. This will be ventilated with the old 120mms once the new ones arrived.
Did you read this?
https://docs.google.com/document/d/1VMO3VfIBy3KIwUaaQ8XhKrSVEbXeeMEqsVhhk6Bz9io/edit?pli=1quote: "Please make it vertically placed if you could. The chips are packaged via QFN, but not all the heat are absorbed by the PCB. The back side will also become hot. And if you have no mechanical setting to lift it and have to lay it on the supporting table, please make sure that there are no heat isolation material under it."