Drainage Gap/Layer Between EPS Foam and Underlayment (and metal roof and underlayment) – GreenBuildingAdvisor

Hello, I’m working on the details for my insulated roof retrofit. I’ve mostly completed the design and the one thing I’ve got a bit hung-up on was the underlayment portions of my assembly. For my original roof deck layer I was planning on using Solitex Adhero Self Adhesive. I spoke with the manufacturer and they said I needed to establish a drainage plane under my EPS foam insulation so that any moisture between the EPS and membrane would have a place to go. I think my solution for this is going to be adding crisscross slits in the bottom of the EPS board like shown here https://buildingscience.com/documents/insights/bsi-038-mind-the-gap-eh#P09 (picture 10), though I’m not sure yet how I’m going to actually add these slits just yet (I’ve got 30 4×8 sheets to do so I need to find something realistic that won’t take 6 months to complete).

Additionally, with the drainage slits in the bottom of the foam I’m now wondering where this drainage should exit my insulation cavity. I’ve attached a mockup of one of the designs (not the actual one, but close enough) that shows how I intended to build a perimeter frame using 2×6 for the foam to sit in, but if the drainage layer is gravity assisted I’m worried I’ll be trapping moisture at my bottom framing board and it will rot over time with nowhere to go. So then I wondered if I should add small slits to this lower level to allow water to escape, but that seemed counterintuitive since I’m trying to make everything so tight by taping everything, so I’m a bit confused how this is normally handled.

For the new upper plywood roof deck above the foam I was going to use another layer of Solitex Adhero, but that might be overkill going under a standing seam metal roof. Since there is potential for moisture to condensate on the back of the metal roof panel wouldn’t I also want some type of drainage plane here as well? I’m trying to find a self adhering membrane product for roofs that has a built in drainage layer and I’m not having much luck. Am I overthinking this and any type of underlayment under the metal roof is fine and a drainage layer isn’t needed?

For reference my project is in zone 5a and will have a standing seam metal roof, with the interior 2×4 rafters filled with rockwool and then Intello. I’ve attached a photo of my mocked up assembly.