Firstly, I will aks for forgivness if what Im about to say is found unrelated and/or offensive.
If you are asking this question in terms of wether or not I know If any scientists have tried validating a forced RLE then no.
But if your asking if I know wether or not ther has been any studies that could help validate it, then Kind of.
Amy Cuddy, offers a ted talk, presenting finding on body luanguage. She talks about how our state of mind affect our body luanguage, but in addition to this shows how, body luanguage can also affect our minds. If you can Id sugest watching it, this talk is very intresting.
This perticular ted talk sugests that, by living in our role, our minds will become acustomed to any scocial changes required to do so. Having freedom to exspress our gender identity, will make us more comfatable in that role.
However, this talk in itself is not RLE validating and has no Trans focus, but can be used to highlight some advantages of RLE.
PS, once again, sorry if I failed to understand your question.