I don't know man.
1. NDU has never been a voluntary affair. If you have the brains
and body, they will take you regardless of your attitude and beat
you into a naval diver.
2. You can throw MC, they may want you to show your MC there and
then reschedule VA for another day. What then?
3. They punish you for bad attitudes but don't listen to those
who say a single MC will beget you punishment. And I heard it's
hard to flunk out after enlistment into NDU.
Therefore, best show you don't have the body by being downgraded
out of the way. Old SAF saying that no body is perfect and it's up
to you to find the problems through specialists. No specialist
memo, no downgrade. Sure, after enlistment, an SAF MO may hear your
credible complaint and refer you to a specialist for free but that
process takes months.