Is there an easy way to reduce the incident energy on a Service Entrance Swbd.
One of the easiest ways to reduce Incident energy of down stream Distribution on a Service Entrance Swbd, is to separate the Main Disconnect from the rest of the lineup.
If the Main has bottom incoming and top outgoing lugs, you can provide a Top Hat above the Main Section. On the Distribution Section, you can provide incoming top Lugs with a Top Hat above the incoming Lug Section, then conduit across to connect the two lineups. I would use some type of fire barrier sealant to make sure the arch can not propagate between the two sections.
Even if you separate the two lineups by a foot, the Distribution is no longer dangerous, and if you employ a Maintenance Switch on the Main, you could reduce the Incident energy considerably.