Re: metal roofing insulation
I haven't seen this specific product you refer to, but:
If you replace your plywood/OSB deck as well, you can apply e-reflective foil insulation (BTUFOIL) on top of your rafters/trusses, then plywood/OSB deck, felt paper and your metal roof.
If you don't replace your plywood/OSB deck, you can:
1. Apply e-reflective foil insulation (BTUFOIL) on top of the deck, following nailing instructions. Then apply your flet and metal roofing.
2. Apply ready cut foil segments (to match your rafters or trusses) under the deck and between the rafters/trusses. Felt and metal roof on top of the deck.
Insulation will reduce your energy consumption.
Always check local codes, which are subject to weather conditions.