Loft to simulate a full round fillet between 3 surfaces

In cases where 3 surfaces meet together and the goal is to create a full round fillet in-between, the top surface could be used to extract an isocurve that’s then used as a middle profile for a “Loft surface”. The two main vertical surfaces are shortened by the amount of approximate radius (in this example, the radius is 5 mm, because the two main surfaces are 10 mm far from each other) and set to tangent start and end for the loft operation. That would maintain the desired top limit for the rounded surface, though it will not produce a true radius fillet.