The vertical epicyclic frequency's cross term is a√M/r^1.5 (radius to the −1.5), following Okazaki 1987. The spec previously wrote a·Ω_φ/r, which makes Ω_θ too large and breaks monotonic growth of precession with spin. Caught during Task 1 implementation by the grows_with_spin test; syncing the spec to the corrected formula that shipped in 891eadf.