i learned to sit fly in that tunnel
although im 65kgs 5'7 and had to wear their baggy suits but it was great fun. i think i spent about 4 hours in there learning lots of flat/back and sit transitions.
having also flown in the new singapore tunnel and also bottrop in germany i can tell you the genting tunnel is very bumpy and slow, but for flat flying and smaller people its great. i would recommend it to beginners who have never flown in a tunnel before so they can learn their tunnel etiquette and tunnel backflying so they can go straight into a bigger tunnel and not waste expensive time learning basics
i met some south africans when i was there, one guy had a prosthetic leg if i remember right not sure if this is the same group?