The latest information I have from Southern Railways (after lots of confusing information), is that the existing gate on the Perry Vale exit will be closed for most of the day. The only exception will be when ticket inspectors are present between 3pm-8pm on weekdays, during the evening peak period, at these times they will manually check everybody's ticket as they exit from the station.
Outside of these hours the gate will be locked to prevent people evading their fare. Passengers alighting on the southbound platform will need to cross over the footbridge and use automated barriers in the station building. The barriers will be in operation for the majority of the day (probably from 6:30am-8pm) when they will be manned. When they are no manned the barriers will be open to allow people through (even when they are evading their fare).
This will make Forest Hill station less accessible than it is currently as people with buggies will need to use at least two sets of stairs rather than one, plus the need to go through the underpass or round under the railway at the South Circular.
I can understand why Southern feel they need to make life a misery for passengers, just to catch those few who try to evade fares. What I really don't understand is why after 8pm the station will be unmanned but only the barriers on one side will be opened - why not open both sides?
Your thoughts and suggestions are most welcome on this forum or this evening at the Forest Hill Society general meeting.