You don't like the excellent bloom that Semogue brushes have?My 610 was a gift from @Macfrommichigan. I’m a face latherer and make a lot of hydrated soap. This brush is effortless. After it drys I place a loose fitting rubber band around the knot . Keeps all the bristles together.
With the Semogue 620 you pay for a boar brush and eventually you get a high end badger brush. Are you with me?