To be followed-up:

• vacuum vessel recovery
• gas connection (long proto): L-shaped connector, position on the side of the manifold
• material of spacers
• HV and RO boards wrt straw layout
  • make them rounded to have more space on the sides 
  • only read out a "cross" of straws - gain space in the corners
• gas manifold material
• how to ensure planarity of HV and FE boards
• how to guide the support tube in the vacuum vessel
• guides or rails for turning the supporting tube in the vacuum vessel
• alignment and positioning of the support tube wrt vacuum vessel
• tooling
• if we had long straws, should we equip the intermediate prototype first?