ehm talking about heat transfer to rig just coz it is from alu is a bit absurd ....
differecies wood/alu/plastic is 0,0nothing in heat transfer ...
dont use common plate or stainless steel ... its too heavy ... 1,5-2mm alu is more then enough and you can buy L profiles in +-6 metres all around your house coz its realy common metal product, then cut it etc ...
or buy shoestander for around 10 bugs .....
edit: yes ofc i made both alu/wood ... alu is sturdy but need a bit accuracy
that shoestander (when you bought it its made in poland maybe coz its absurdly "bad" cutted and wierd material at all ...) need stronger stands + some tapes to make it sturdier but the rest is made just exactly for this useage