Decoupler

Suggestion:

A block that splits itself in half or detaches block connected to it when triggered, but otherwise is treated as a single block.

Differences from merge block:

• Does not require power to stay whole, requires power to decouple
• When welded, starts whole (this will simplify building from blueprints a lot!)
• Single use (potentially even requires explosives to build) until repaired. Potentially vanishes entirely once triggered. Not re-attachable, but re-buildable.
• Pushes halves/parts one from another once triggered

Reasons:

• Merge blocks aren't optimal for building and detaching blueprints, they tend to fly away in some cases during welding progress, neither push parts away from each other when triggered.
• Variety. Variety of active build blocks is one very weak points of Space engineers.
• 1x1 or 1x2 small grid decoupler is probably cheaper performance wise than using small rotors and has advantage of being projector-friendly.

P.S. Directed explosive charge block that warranties destruction of block it is welded onto will also be a fine option. Might be even better than Decoupler in some aspects.