The biggest problem I've seen with cg hooks is in combination with tail skids on early gliders, like our ex club mini nimbus. With a good tail wheel, you get a lot of crosswind directional stability in the early part of takeoff roll.

You won't ground loop on takeoff until a wing goes down and starts dragging.. The nose hook is only useful if you plan to leave the wing down, dragging away, hoping to pick it up, and rudder isn't enough to keep the glider straight. Releasing might be a better plan -- and now it doesn't matter where the hook is.

On modern gliders, I can't see how uncommanded kiting is a problem on airtows. Lots of elevator authority, c.g. or not. The extra pitch up moment from the cg hook is -- except for unbelievably rare circumstances (Robertson crash) -- plenty

John Cochrane