Necessity of hard set-theoretic techniques

Determine whether hard set-theoretic techniques are strictly necessary to prove the existence of a Polish metric space with FFKN rank d714.

Background

The paper constructs a Polish metric space whose FFKN rank is d714, thereby showing that the previously known upper bound is sharp. The proof uses substantial set-theoretic methods, including inner models, absoluteness, and condensation arguments. The author explicitly leaves unresolved whether this level of set-theoretic machinery is genuinely indispensable.