Question on Second Order Reliability Method (FORM) Theory in UQLab V2.1

Hy everyone. I was reading the last publication UQLAB USER MANUAL STRUCTURAL RELIABILITY (RARE EVENT ESTIMATION) where the SORM start with:

and subsequently the condition of the Equation 1.30:

And subsequently Equation 1.29 rewritten as:

My questions are:

  1. For the definition of V_m to be correct, Equation 1.30 should not be U=Q^TV ?
  2. And what is the reason for the disappearance of the transpose of (U-U)^T from Equation 1.29 to Equation 1.31?

Thanks and regards.