If the Ensolite is loose near the seams, I'd reattach it first. Contact cement, maybe? If there are any bubbles, make a very small hole, inject adhesive, and push back into place. Contact cement is nice because if you let it get tacky before putting the pieces together, they will grab and hold.
Clean very thoroughly.
Then caulk. I'll say it again- paintable latex, not silicone. Even if the seams are wide, or if there are gouges in the Ensolite, just fill them in with caulk. Smooth with a damp rag or finger, then texture if desired. Let it cure thoroughly.
Next prime and paint
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