Developing shadow functions proves to be something that is ultimately useless to the self.
Socionics, for instance, incorporates the Shadow Functions into the Super-Ego and the Id Block.
The Super-Ego block is extremely loathed and thought of as one's characterizing flaws (mainly the PoLR, which is practically a blindspot for sociotypes)
The Id block is deemed tedious and unnecessary, to the point where its existence nags the sociotype by forcing him/her to do work for those functions that they do not particularly find helpful.
Therefore, assuming that the two models are equally translatable, developing the shadow functions will only lead to personal misery in the form of embarrassment and self-loathing (Super-Ego) or doing something that is tedious, boring, and vapid (Id).
Also, the Beebe model shows how nasty shadow functions can be, such as the trickster function (Socionics equivalent = PoLR), which is seen as the evil that ensnares the individual into playing its little games and losing and even projecting one's complete failure to use the function onto others.
Socionics specifically says that to be happy, one must stick to one's own guns in the Ego block, and find one's dual to satisfy the unconscious desires of the Super-Id block.
JCF specifically says that to be happy, one must develop one's lower functions and learn from them, usually citing the inferior function as one of profound wisdom and transforming nature when expressed positively (juxtaposing the insidious evil of the Demonic Personality Complex when expressed negatively, corresponding to Socionics's Role Function, that which suppresses the Hero (Lead/Dominant)).
The only shadow function that could be considered as relatively useful is the Demonstrative Function of Socionics or the Witch/Senex function of JCF, due to its unconscious affect on one's own worldview and, specifically in Socionics, provides the user with a way to protect one's dual's PoLR from others (as one dual's PoLR is the other's Demonstrative), meaning that the sociotype can defend its dual from harsh criticism with relatively strong force against Ego-valuing types of the Demonstrative function.