Alright so at end I did something like previusly posted and i was able to check if the DLC was unlocked or not with the following code:
public void CheckForAchievmentUpdates()
{
Achievements.GetProgressByName(new string[] { FinalString }).OnComplete(
(Message<AchievementProgressList> msg) =>
{
foreach (var achievement in msg.Data)
{
if (achievement.Name == FinalString)
{
Debug.Log(achievement.Name + " :"+ achievement.IsUnlocked);
}
}
}
);
}
However I'm not sure Oculus.Platform.Achievements.Unlock("Collector"); is enough to completely unlock the achievement or there's something else i should call to make sure the acheivement is unlocked and saved as such.