Cutting/fragging large colony frogspawn

[Thenakedreefer]

Anyone with experience fragging older large colonies of frogspawn know how far up the stalk I can safely cut? I.e. how close to the head can it be cut. For reference the stalks in the image are about 4-5 inches long.

 

[A Young Reefer]

red region is where I wouldn't touch the coral, due to the presence of flesh.
I would leave a few centimeters to be safe and proceed with cutting, which I marked with green.