1. Is this an all-metal hotend?_br_2. Does it have a bi-metalic heatbreak?_br_3. How hot can I have it? is it suiteble for Nylon or PETG?_br_4. How is it different from the one for the board V4.0? how are both boards different that it is not compatible with each other?_br_5. Can the nozzle be exchanged to any MK8 nozzle?