if you mean render - time extrusions, yeah they are interpolated by some automatic criteria. Old fashion trick to override this, is to create Self.ShapeResolutionV attribute, feed it with some integer, let's say strand segments count, probably plus or minus 1 to that value.
This makes extrusion linear, by strand segment. Now if you want same profile, even on high angles, you need higher stand size on corners.... by factor 1.41 ( square root of 2) on 90 degree, something arbitrary on higher angle.
If all segments are linear, maybe it's better to go with another point cloud, created from strands, which just replaces strands with cylinders or capsules.