I've been gripping with this issue for a while and I finally figured out a decent way to do this semi-manually using the Fuse SOP. I found some methods that use clipping, but I thought they were too complex to use realistically.
My advice here is not really applicable to your example since you are intentionally causing the issue by putting the points too close together, and could easily fix it by moving or deleting the points that are too close together away, or scaling down the cross section. In my example, I started with a Bezier curve and it was resampling that put the points too close together.
I initially fixed it manually by Blasting some of the points around the affected corners with manual selection, but now I found a much better solution. It turns out that you can pass in the original (non-resampled) curve as the second input into Fuse and use the corner selections on it as the target snapping points. You can then set a distance from those points. The SOP can also output the snapped to points as a group which you can pass into PolyBevel in order to smooth out the sharp corners. Before that, in the Group Promote select to include only the elements on the boundary.
Using the Fuse SOP is more robust than Blasting the points by hand since changing the resample length would not break the downstream node selections.
