My ski locker is full of the kids stuff and oars and whatever else. That is a good Idea. When my racks come in today or tomorrow I will head out and try and reorganize everything.
You may be out 90', the original rope plus 30' off ball or possibly more. IMHO I am uncomfortable on crowded lakes going that far back, seen some nasty things happen even a death when someone hit the tuber in the chop on a Jet Ski. Also remember that if the rider falls you are going to move forward a bit till you spin around and I personally don't want my rider that far away from me in the water, especially with some of the nut jobs I see riding around on jet ski's in an unsafe manner and why to close. If there is an issue I want to be close enough to punch it and get between my rider and whatever is coming at them. Your water may not be too crowded.
Also when you do the pendulum swing, crossing the wake, the tube will accelerate - which I have read in excess of 55-60 mph or more, the longer the rope the more speed, to the point of dangerous. I also think you had a hard time having them cross the wake because of the length of the rope which I believe makes it more difficult. I don't over exaggerate the swing at all for safety reasons, just enough to get the moving back and forth consistently so they can bounce over the wake. Note: In my younger days when I was a competition Slalom and barefoot Skier, we would take a donut tube and do a lot of stupid things with it, hit the water so hard I blacked out.... dumb, dumb, dumb. Luckily everyone lived through it. I guess with age comes wisdom and common sense.
Just my thoughts, I will digress to those with much more experience and wisdom than I.