Regarding famous “fake it until you make it” approach some people deem that success is to fake so believably that others think you are not faking, and that the only thing needed for this success is practice.

I would say the most important aspect is how this experience (this role-play) affects inner state (state of mind, soul etc.) of the faker (the role-player) and what kind of feedback loop (uplifting or depressing) it creates. I would consider successful a “fake it until you make it” experience which increases belief of the role-player (faker) that what he/she just faked is actually possible and reachable for him/her, an experience which increases ones self-esteem (in the area where “fake it until you make it” is applied) and helps to sight surmountable obstacles. Often resolution of these surmountable obstacles creates further positive feedback loop. Sometimes during the faking lack of already surmounted obstacles can be spotted, providing immediate positive feedback and increased trust in further success.
A “fake it until you make it” failure, I would say, is an experience which ruins trust of the role player in actually reaching the faked thing (in other words, experience that makes faker believe that he/she will never “make it”). Such failure may create further psychological blocks and emotional trauma making even harder to “make it” at some later point.

In case “fake it until you make it” approach fails or looks inappropriate (most likely will fail if tried), inner work methods like Family Constellations (or may be Usladushka’s method in some spirit-related cases) can be used to heal the root cause of the issue. Sometimes after inner work “fake it until you make it” approach becomes successful, sometimes it is not even needed. But sometimes after inner work a step in physical world towards the goal is needed, and sometimes this step can be faking reaching the goal until it is actually reached.