I hate that fight.
It's a simple puzzle that basically ignores D&D combat rules and revolves around exploiting the environment, turn based system and a dumb AI you can control.
If you replay the fight with a new party it wont be any different from before. Solve the puzzle you already know how to solve. Handing out extreme immunities and vulnerabilities is not interesting, especially when you can just right click to basically metagame to learn them.
Level 4 PCs shouldn't be fighting Adamantine golems anyway. There are more appropriate enemies for bosses at those levels.
