without appropriate training with an FI.
'Sounds as though there was a shortage of this already, if 1.7Vs approach is being considered!
What about foreign pilots and FI spinning their DR400 ? This procedure is strictly forbidden in the country of the manufacturer of this aircraft.
Out of curiosity, I search the DR400 flight manual. Spinning is prohibited in the representation of the limitations placard on page 2.08. So spinning is prohibited, unless there is a special authority, which is done for valid reasons. So if pilots are spinning DR400's during casual flying, they are flying outside the limitation, and not legal. Subject to enforcement action, and no insurance.
For your reference, as all certified single engine airplanes, the DR400 will have been spun during certification, but the manufacturer chose not to certify if for spinning. Likely because recovery risked exceeding limitations too easily.
If in doubt about what a particular 'plane is permitted to do, or how it should be flown, read the POH and placards.