its 50/50 for me
if you have never faced 85mph then you can not play it or probably even see it, simple as that. If you spend 6 months in the nets with the ball at 85mph then by then end you should be ok to see it and be comfortable. Whether you can play it well depends on talent.
When we were under 15s our coach used to spend the first 5 mins with the machine set at 80mph, left arm over, angling across us, well pitched up outside off stump. There was no need to play it. The last 5 minutes would be the same. The 10 mniutes in between would be at 60mph. Trust me on this, the 60mph felt very very slow. As time went on you got a little more adventurous and started to get in line with those 80mph balls and try to drive them.
give it a go.
1. you'll be suprised how quick 80-85mph is!!
2. you probably cant hit it
3. youll get comfortable with it
4. youll eventually conquer it
having it short and simulating short bowling is a big no-no!!