Learning Fiore De Liberi

The swords in these wards should be unstable in their relationship to the line. This means that on the defense, the will generally be better coming off the line, and returning to it then staying on it. Attacks from these wards are also better to come off the line, and return to it as well, thrusts being the exception. When laying in these poste, keeping the blade looser, or even moving it is better then leaving it motionless.
When laying in these wards, I don't advocate movement that endangers you. Some people (especially new ones) will be intimidated by an opponent in Poste Longa waggling their blade like an epileptic weasel on speed. Some people won't. Some people will watch the tip, and so a slower wider movement might be better. Others won't fall for any of these tricks, and so just holding (not in the sense of gripping the sword) the blade loose with regard to the line is better.
The key is the relationship of the sword to the line, not the tactics that you use. The tactics you use should be determined by your situation and your opponent, the governing philosophy of these wards is that they are flexible with regard to the line.