  The emergence of large-scale magnetic fields observed in the diffuse
interstellar medium is explained by a turbulent dynamo. The underlying
transport coefficients have previously been extracted from numerical
simulations. So far, this was restricted to the kinematic regime, but we aim to
extend our analysis into the realm of dynamically important fields. This marks
an important step on which derived mean-field models rely to explain observed
equipartition strength fields. As in previous work, we diagnose turbulent
transport coefficients by means of the test-field method. We derive quenching
functions for the dynamo {\alpha} effect, diamagnetic pumping, and turbulent
diffusivity, which are compared with theoretical expectations. At late times,
we observe the suppression of the vertical wind. Because this potentially
affects the removal of small-scale magnetic helicity, new concerns arise about
circumventing constraints imposed by the conservation of magnetic helicity at
high magnetic Reynolds numbers. While present results cannot safely rule out
this possibility, the issue only becomes important at late stages and is absent
when the dynamo is quenched by the wind itself.
