Can I insulate the engine shroud?

Lowes sells a roll of insulating material with Al foil on one side about 1/2 in thick that was relatively cheap. Much cheaper than Dynamat or some of the other automotive or boat insulations. I added this to mine and it made a big difference in sound and heat reduction.

Or simply use cowling heat shield/ soundproofing from a boat shop. It's the same stuff used to line generator compartments.

After you put on the heat shield also put a layer of sound proofing material to make it more quiet.

Yes.