So, what's the best way to go about evaluating a device for class 1 div 2 ( or Zone 2)
My experience with explosion proof is that it's all in the enclosure. When I worked for an industrial power control company we would put our normal NEMA 1 rated equipment into massive steel enclosures with bolts every inch or two inches and it would meet all explosion proof requirements.

Crazy expensive enclosures, mind you, but the requirement is that if explosive vapours were present and a relay were to arc or a component fail and a spark be present, that it won't cause an explosion.