Am not sure if I understand exactly what you want to do but if it is to support insulation
with aluminium perforated sheet over it then -
Have you thought about using glue on stainless steel insulation
stick pins? - these will be listed by insulation materials suppliers. These are pins that have a big flat base which one glues to the hull
overhead, then the insulation and its facing (usually heavy foil) are pushed onto the pin, a big friction held washer is then pushed down the pin to secure the insulation and the pin then clipped to length.
All the boats I have been involved with have used foil faced insulation but you may find that the pins will also hold light perforated sheet over the insulation - only possible problem might be in lining the pins up with the perforations.