Dense Sheets on Shelving Meet Misc. Storage?

I’m looking for some input on a storage condition that doesn’t fit cleanly into typical rack storage criteria.

We have laminate sheets (55" x 121") stored horizontally on shelving. Material contains Class C plastics → treating as a Class III commodity. Configuration: Sheets are stacked horizontally on closely spaced solid shelves. Shelf spacing is tight (a few inches). Essentially continuous solid shelving (no vertical flue space). Overall storage height is ≤12 ft.

This is not traditional pallet rack storage — it’s more like dense horizontal sheet storage with multiple solid shelf layers.

If the overall storage height does not exceed 12 ft, can this be treated as miscellaneous storage per NFPA 13, assuming all miscellaneous storage criteria are met?

Or does the presence of closely spaced solid shelving (acting like stacked horizontal obstructions / solid shelf rack condition) prevent use of miscellaneous storage and instead trigger solid shelf rack criteria and/or in-rack or intermediate-level sprinkler requirements?

The concern is that even though the storage height is within the 12 ft miscellaneous threshold, the shelving configuration completely blocks vertical water penetration and behaves more like stacked horizontal barriers than typical low-piled storage, so I’m questioning whether miscellaneous storage criteria is even applicable here or if the configuration itself drives the protection method regardless of height?

How others have classified similar flat sheet / laminate storage on tight shelving whether AHJs/FM have pushed this into rack/shelf obstruction criteria instead of miscelleneous storage?

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