The aluminum cap, yes...The steel cap on the DA and 3W wires almost takes a screwdriver to get it off...No need for a clamp on those...
The steel cap on the Falkon ignitions I have here is looser, a clamp would be a good idea on those...
If someone is going to copy a cap, why not do it right ?
I haven't seen a Chinese cap here, but it looks like they need a clamp too...