The conjectural presentation of the valuation algebra of complex space forms

Define the formal series $\f_k(s,t,\lambda)$ by

$$\log\left(1+s x^2+t x+\sum_{n}\left[\binom{4n+1}{n+1}-9\binom{4n+1}{n-1}\right]\lambda^n x^{-2n}\right)=\sum_k \bar f_k(s,t,\lambda)x^k.$$

The presentation conjecture. For the valuation algebra $\mathcal{V}^n_\lambda$,

$$\mathcal{V}^n_\lambda\simeq \mathbb{R}[s,t]/(\bar f_{n+1},\bar f_{n+2},t^{2n+1},st^{2n-1},\dots,s^nt).$$

This was the first conjectural description of the algebras $\mathcal{V}^n_\lambda$ for $\lambda\ne0$, before the isomorphism and structure theorems established that the algebras for fixed $n$ and varying $\lambda$ are isomorphic as filtered algebras. The source gives no explicit resolution status for this initial conjectural presentation.