here are a few more ideas...
Various different other things you can do.
Starting with using a training bat, or just one hand on the bat.
Then trying some spin, but putting the bowling machine at 45 degrees? that is relatively effective if you get the settings right.
Have you tried varying the speeds too? Practice against a 50-60 mph dot ball bowler for a session then a proper quick – the change in speed and length will mean you get a different challenge.
What about working in some fitness, so face 10 balls then do some fully kitted up shuttles, then face another ten balls etc. Batting is tough when you are knackered.
Also work game situations, think having the bowler bowling around the wicket to a leg side field of a deep set off side field.
You could also use cones to try to hit 'gaps' making them smaller and smaller.