It's not really clear what your question is. The efficiency measures (I think, it's not really clear what efficiency is being calculated) indicate how close to orthogonal the design is.
The design has advantages and disadvantages, which you need to weigh in your mind so you can decide if you want to use it. Efficiency does not negate the disadvantages mentioned.
Advantages:
Small
All main effects estimable
Orthogonal (Efficient)
Disadvantages:
No degrees of freedom for error
No interactions estimable
If interactions are present, then they are confounded with main effects
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