Can't say it for sure but I think these are not really traditional I think it's just a way to use them in a more street show way... Mr Liu at that time didn't want to hear about something like that... He was already shocked enough when we started inventing the Toupétanque!
So from this fact you/we can make it the way you/we want...
We wanted something strong enough to support Taiwan top bad throws (like my arch one) but we avoided metal for tips safety for the very same kind of throws... I think metal should be used when only experimented throwers... At least for the tips...
For same reasons we completed the platform rounded with some rubber tube... At least on the tall one to avoid shocks on the metal circle and the top coming from down...