Corky Meyer did wing tip separation test flying in the Bearcat, what follows is abbreviated from the full story in his book Flight Journal.
Grumman knew about the problem before the aircraft entered service, and carefully designed a joint in the wing and aileron about 3ft in from the tips so both would separate at the same time.
They were also required to demonstrate takeoffs and landings with both, then alternate tips removed.
However, once in service there was a fatal accident when only one tip separated on a dive bombing pullout.
It was after that acident that the idea of blowing tips off was tested, and after some problems was approved for service.
Prima cord was used at the joint, cross connected with micro switches so that if one was pulled off the other would blow off.
However they had not built in any safeguards against maintainance mistakes, and in service on a carrier there was a short circuit which blew off the tips and fatally injured a mechanic.
That was the end of the blown tips idea.
The tips were firmly fixed in place and the load limit was reduced to 4g; but then pilots were exceeding that limit and wings were coming off at the root.
This was corrected by beefing up the structure so that the G limit was increased to 7.5.