I'd be more inclined to believe the manufacturer specs than what an unaffiliated electrician tells you.
At the very least, if going with his word, I'd want written confirmation from his insurance company that they would cover any issues arising from an install against the manufacturer instructions.
important to install to that spec for compliance, the actual figure was a misnomer
was not clear: Our electrician installed to spec per the maximum load, and made it clear that he was not and would not suggest otherwise, the discussion was merely academic.
I'd be more inclined to believe the manufacturer specs than what an unaffiliated electrician tells you.
At the very least, if going with his word, I'd want written confirmation from his insurance company that they would cover any issues arising from an install against the manufacturer instructions.