How to change DesiredToolTipLocation

I would like to position tooltip at a specific location for some tooltip.

I’ve checked the code and the tooltip location is stored in DesiredToolTipLocation within FSlateApplication
The problem is that var is private and the only way to change the tooltip location is to use

void FSlateApplication::SpawnToolTip( const TSharedRef& InToolTip, const FVector2D& InSpawnLocation )

The problem resides in the fact I don’t know when to call this function.

If I call this function within the OnOpening() call-back, it fails since the tooltip (this) is destroyed before updating its position.

void SKPickupObjectTooltip::OnOpening()
{
        .................
        .................
        .................
	SKTooltip::OnOpening();
	
	FSlateApplication::Get().SpawnToolTip(TSharedRef<IToolTip>(this), FVector2D(100.0f, 100.0f));
}

Is there a way to set the DesiredToolTipLocation var ?