The QLD gov web site is pretty spot on with there trail description and the need to be of above average fitness.
Although at the 3.3km mark where the wire fern patch begins the trail actually gets easier not harder. The main factor is time and not getting stuck on the mountain in fading light as the trail is not well used and ribbon markers are your only guide.Once past the fern patch the terrain become undulating so it is much easier to get disorientated .
Beware of leaches from about 2.5km -3.3km .Rest standing do not sit on logs or the ground, it is teeming with leeches, plenty of repellent on the shoes will help keep them at bay.
Wait-a-While or climbing palms are all over the track aswell as spiky trunked palms , very hard to avoid or grab trying to steady yourself. I suggest gloves and a hat for protection.
Get going on first light to avoid the heat on the way up and to give yourself plenty of daylight good luck.