lomapaseo (re locked-rotor starting):
Perhaps there is a corralary somwhere in the turboprop world of starting vs the prop speed
The 2-spool turboprops/turboshafts I'm familiar with are all approved for locked-rotor starts. VH-3D
Marine One is an example, with core engines running but the helo rotor braked to a halt when
el presidente embarks/disembarks.
And the CT7 turboprop has an extra pad on the prop gearbox for mounting a disc brake - but I don't know if any customers have ordered this option.