How much more she can stretch? Liberty haze

Pre-flower stretch usually lasts about 1-2 weeks so you're probably nearing it's end (considering she also doubled her size). if she still rapidly stretches you can try more tying and spreading for more lateral growth, it might be difficult with the limited space you have so be careful! Super-Cropping is a HST (High Stress Training) which means it'll cause immense stress on your plant and may stunt growth for a few days before it becomes beneficial, this may be manageable while in veg but when flowering it most likely will harm your plant and diminish yields. I do not recommend Super-Cropping after 1-2 weeks before flowering is induced!! You can also check my Super-Cropping experience in my Diary and get an idea of what it is. Hope this helps! Good luck and happy growing :)