As expectable, the mentioned literature doesn't say a word about a "single phase" motor being better in VFD applications
any way. The only motivation for these designs is the obvious fact , that the motor type is very common and it doesn't pay
in some cases to redesign an existing motor.
Because the presented circuits are full three-phase bridges, the electronic part count isn't different from a standard three-phase
motor drive. But due to the unsymmetrical currents, the ultilization is worse, you also have higher bus ripple current and a pulsating
torque and possibly higher control effort.
Apart from this, I keep my opinion, that these motors should be better designated two-phase motors according to their construction.