Modernizing the unbuilt 1920 South Dakota class

Would the unbuilt 1920 South Dakota-class battleships have modernized more easily than the Standards?

Only somewhat: they would need better engines and air defence, but their powerful main guns would not require replacement.

The unbuilt South Dakota class would be only somewhat more adaptable than the US Standard-type battleships. Its air defences and engines would still require major modernization. The original firepower was the advantage because the main guns would remain adequate enough to avoid replacement. Machinery and anti-aircraft requirements would age faster than the heavy battery.