It is impossible, with the exception of the PMI sector. Stansted indeed separates arrivals and departures, so does AGP and IBZ. For STN there is a transfer channel just before passports but it won't save much time, it's quite a spread out airport with transits connecting the piers. IBZ and AGP would also be difficult at peak times, their arrivals areas get chocked up quite easily. PMI mixes inbound and outbound passengers at the gate, with the risk of a bus transfer, but that should still be OK.