  We present results from the first public data release of the MaNGA-ARO Survey
of CO Targets (MASCOT), focussing our study on galaxies whose star-formation
rates and stellar masses place them below the ridge of the star-forming Main
Sequence. In optically-selected type 2 AGN/LINERs/Composites, we find an
empirical relation between gas-phase metallicity gradients $\nabla Z$ and
global molecular gas depletion times $t_\mathrm{dep} = M_{H_2}$/SFR with "more
quenched" systems showing flatter/positive gradients. Our results are based on
the O3N2 metallicity diagnostic (applied to star-forming regions within a given
galaxy) which was recently suggested to also be robust against emission by
diffuse ionised gas (DIG) and low-ionisation nuclear emission regions (LINERs).
We conduct a systematic investigation into possible drivers of the observed
$\nabla Z$ - $t_\mathrm{dep}$ relation (ouflows, gas accretion, in-situ star
formation, mergers, and morphology). We find a strong relation between $\nabla
Z$ or $t_\mathrm{dep}$ and centralised outflow strength traced by the [OIII]
velocity broadening. We also find signatures of suppressed star-formation in
the outskirts in AGN-like galaxies with long depletion times and an enhancement
of metals in the outer regions. We find no evidence of inflows impacting the
metallicity gradients, and none of our results are found to be significantly
affected by merger activity or morphology. We thus conclude that the observed
$\nabla Z$ - $t_\mathrm{dep}$ relation may stem from a combination of metal
redistribution via weak feedback, and a connection to in-situ star formation
via a resolved mass-metallicity-SFR relation.
