It seems over the years, as with Avoncliff and Freshford, we've had request stops turn into full stops, but I wonder what the newest station to become a request stop is?
My bet is Conwy, having reopened in 1987 after being closed for over 20 years.
The only request stops I have used recently have been Dyffryn Ardudwy and Talybont on the Cambrian Coast line, and have had no problems joining the train there. That said, on one occasion I got off fine, my friend's bag got caught around the luggage rack and another passenger got on after I had got off, the guard preceded to close the doors to which I had to make rigorous hand movements, then the guard opened the doors and my friend could get off, with luggage.
I think the Cambrian Coast timetable factors in that the train is unlikely to stop at every request stop, and this seems fairly accurate. Though on a journey back down, we stopped at every station between Dyffryn Ardudwy (Where I boarded) and Penhelig (other than Llanaber) (6 request stops and 4 compulsory). When selling the tickets, the guard said the train had been stopping everywhere today, which made sense and the train was about 10-15 minutes late into Dovey Junction, where the Aberystwyth portion was waiting for us to pass.