Fills:

1) New algorithm for connecting along the perimeters is now applied
   to Honeycomb, Hilbert and similar planar filling curves.
2) The old expensive path chaining is not applied if the new algorithm
   to connect along the perimeter lines is called afterwards.

src/libslic3r/Fill/FillGyroid.cpp

@@ -190,11 +190,10 @@ void FillGyroid::_fill_surface_single(
 			polylines.end());
 
 	if (! polylines.empty()) {
-		polylines = chain_polylines(polylines);
 		// connect lines
 		size_t polylines_out_first_idx = polylines_out.size();
 		if (params.dont_connect)
-        	append(polylines_out, std::move(polylines));
+        	append(polylines_out, chain_polylines(polylines));
         else
             this->connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);