In the 2025.1 Update, we've continued to improve the Corner Blend tool by providing the ability to create blends between four intersecting surfaces.
To create a blend of four intersecting fillets, select all four surfaces, either by picking them individually or by box-selecting, then click Build. The Corner Blend control window automatically populates the tool control window with attributes for the four surface blend. Under Blend Surface, use the Edge Shape 1 through 4 sliders to adjust the resulting CV layout of the blend.
If you want to create a blend with three surfaces and a base surface, the selection sequence is the same as in previous versions.
When building a three fillet corner blend, you'll notice that the letters A and B now display with the edge adjustment manipulators.
For more information, see Corner Blend.