"I practice flying my kite in my own time already, I don't want to have to pay someone for a couple of hours just to fly their trainer kite so I can then learn the things I need".
Hi mate,
Just a note, I find it advantageous for my students to gain trainer kite flying skills before we venture out.
Developing a basic skill set, I find from experience maximises the productivity in the lesson.
I think you'll find that IKO instructors will always use kites that are suited to the conditions for 'kite boarding' not just practicing as you put it on a trainer, unless you specify that is what you require.
We do down winder lessons in Botany Bay that allows the student to ride non-stop. This is a benefit to all levels as you'd gain mileage and get coaching through a radio helmet. This is of course done after all safety is covered including the self rescue.
My point being that your quote above is a very loose and I think that you would perhaps benefit more than you think from taking a lesson.
If your ever around the bay in Sydney I would be more than happy to show you the self rescue.
Good winds and good luck

T