1. If possible orient horizontal leg perpendicular (appears at 45 Deg to me) to nozzle axis to absorb radial movement from nozzle and vertical expansion.
2. I hope you have started with simple EJ such as tied universal etc. prior to using 2 Gimbal EJ's
3. For the 7m spool between EJ's, you may provide a spring support.
4. What are the restraints in the vicinity of EJ?