I'm all for doing double leg if the patient can't manage single leg. But like you say they may be a bit far off that still.
If ACP provides benefit then definately pursue it. If your getting benefit then keep on doing what your doing. At which point a plateau is reached then we should look into the eccentric protocol perhaps. I would almost say they are contraindicated as the eccentric work is shown to reduce the vascularisation in the tendon and I think ACP is attempting to increase it? Fill me in if I'm wrong on that.