Rationality conjecture for linear relations among brackets

Let a collection consist of mono- or bi-brackets, viewed as elements of the relevant bracket algebra over $\mathbb Q$ and $\mathbb C(q)$. Rationality conjecture for bracket relations. A collection of (bi-)brackets is linearly dependent over $\mathbb C(q)$ if and only if it is linearly dependent over $\mathbb Q$. This would mean that all linear, and hence algebraic, relations among the brackets are defined over $\mathbb Q$ rather than requiring coefficients in $\mathbb C(q)$; the source presents this as an expectation and gives no resolution.