Hi Kwin, yes I think like Brian says Network is working well for this.

So to do that you would select these 4 curves:



Then run Construct > Network to make this result:



So one thing about Network though is that when you have the curves in one direction like this one:



Collapsing down to a single point up here:



It can help to get better shaping by having an intermediate curve to even out the shape before it squeezes down to a point, like this:



So then that will generate a result like this (3DM attached):



- Michael