= Solution
Let $\phi=j\pi/2$ for an integer $j$, and put $q=j\bmod2$. Use the fixed phase-measurement angles $(\theta,0,-\phi)$ and a fixed final <computational basis> measurement. Denote their outcomes by $k,l,m,s$. The adaptive construction would instead use $-\phi$ when $l=0$ and $+\phi$ when $l=1$.
For the printed measurement vectors,
$$
|v_t(\eta+j\pi)\rangle=|v_{t\oplus q}(\eta)\rangle.
$$
Therefore $+\phi$ and $-\phi$ define the same unordered pair of rank-one <linear projections>; the labels are exchanged if and only if $q=1$. In the branch $l=1$, the outcome that would be called $m_{\mathrm{ad}}$ in the adaptive experiment is thus $m\oplus q$. In both branches,
$$
m_{\mathrm{ad}}=m\oplus ql.
$$
The output correction from the preceding part becomes
$$
\boxed{r=s\oplus k\oplus m\oplus ql.}
$$
If $j$ is even this reduces to $s\oplus k\oplus m$; if $j$ is odd an additional $l$ is included. This <equatorial measurement relabeling at Clifford angles> changes only the classical interpretation, not any physical measurement basis.
All four fixed single-<qubit> <projective measurements> act on different vertices, so their operators commute. They can be performed simultaneously, with the displayed classical correction applied afterward. The first angle $\theta$ may be arbitrary: it was never adaptive. Only the sign choice for the third angle needed to be replaced. Thus \b[the simulation is nonadaptive for every $\phi\in(\pi/2)\mathbb Z$].
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