In this paper we consider the effect of a topological Maxwell term
W(Φ)Fμν​F~μν on holographic transport and
thermodynamics in 2+1 dimensions, in the case with a dyonic black hole in the
gravity dual. We find that for a constant W the modifications to the
thermodynamics are easily quantified, and transport is affected only for
σxy​. If one consider also the attractor mechanism, and writing the
horizon transport in terms of charges, the transport coefficients are affected
explicitly. We also introduce the case of case of radially dependent W(z), in
which case, however, analytical calculations become very involved. We also
consider the implications of the two models for the S-duality of holographic
transport coefficients.Comment: 25 pages, no figures; clarifications adde