The variation of the selectivity, defined as the yield of one reaction product divided by the total product yield, with the residence time in a model scheme based on "mutating autocatalysis" is considered. Operating conditions spanning several types of bifurcation are investigated and the selectivity observed from time-dependent integrations compared to those appropriate to steady-state operation, In one case, complex periodic solutions may develop through a period-doubling bifurcation sequence, leading to chaotic states. The simple proportional feedback method is used to compare the selectivity of different stabilised periodic orbit under these conditions. It is found that these different states all have similar selectivities to that observed in the autonomous chaotic state, but that a significant change in selectivity can be achieved at the same operating conditions by targeting a coexisting stable period-1 orbit lying on a separate branch of solutions.