Whilst a catch-point would protect the 'drop'.. Where would the 'caught' loco end-up?
I could see a track-powered loco coming to a stop on the ballast. - Suitable fence to edge of base-board(s).. But a battery / steam loco will just keep going.
You need to physically catch / restrain a still-moving loco?
Which is why I am considering a barrier in the middle of the track or across it to stop the loco leaving it on the tracks with wheels spinning.
Still thinking about this problem.