What little I know of this issue suggests that earlier intervention might be better for the person because of the hormonal synergy triggered by testosterone level. Testosterone is not just a sexual hormone. Levels of testosterone determine a whole spectrum of metabolic, physiological and neurological growth dynamics which shape the mind and body of a person significantly for their entire life. Better to let the body follow one specific direction rather than two so that conflicts and/or impediments to optimal functionality are less likely to arise.
Since I've read nothing on this topic specifically, it would be necessary to study what experts in hormonal development and in sexual development (both physiological and psychological) have to say about the pertinent factors. If physiological ambisexuality conferred some sort of advantage on a mammal, it would have emerged in the natural environment, but it hasn't. The only animals which are ambisexual are the lower ones, such as insects, reptiles, amphibians, mollusks, etc. So it may be appropriate to view it more as a deformity or at best a gross deviation from normal rather than a matter of being an "alternative" condition.