Would a Kongo make a better carrier conversion than Kaga?

Would converting a Kongo-class ship have produced a better aircraft carrier than Kaga?

Probably not overall; Japan needed the Kongos in their existing roles, treaty tonnage complicated the substitution, and losing Amagi was the larger carrier setback.

Kaga is the preferred conversion candidate despite the attraction of a faster Kongo hull. Japan still needed the Kongos for their surface and carrier-group roles, so surrendering those ships would create another force-structure gap. The treaty tonnage released or consumed by a Kongo conversion would also not necessarily support the desired carrier program as effectively. The loss of Amagi after the earthquake was the more consequential blow to Japanese carrier development.