BMI is very useful for cosplay. And I think I remember you saying that we could, in principle, impersonate Ligier.
Speaking of BMI - does it come with a side of intellectus? It's a perfect disguise charm, right? So, for example, we could transform into Maeve. We have seen Maeve, but we don't know if she has a tattoo somewhere under her clothes. However, BMI is a perfect disguise charm, so it would need to imitate said tattoo even if we don't know it exists. So, it would need to pull information from somewhere, Crown of Eyes style.
In general, what are the limitations of BMI? What do we need to know about a person in order to imitate them? Is just the knowledge of their existence enough? Their name / what they are called? Their true name? General knowledge of their appearance? For example, could Molly use BMI to make herself look like a random inhabitant of one of the planets she knows aliens exist on?
Further, BMI explicitly allows fictitious characters to be imitated. This is exploitable in a number of ways:
1) For getting information. For example, in an excellent book
Jonathan Strange and mr. Norrell (published in 2004, so should already exist in-story), there's a character Vinculus, who has the book of magic knowledge and prophecy tattooed on his skin. If Molly was to BMI to look like him, would her tattoos should useful knowledge of magic? If she was to impersonate Master Chief, would Cortana come through (if that's too removed, what about Johnny Silverhand from Cyberpunk 2077 if Molly was to impersonate V)? If she was to invent a fictitious character herself who had "all the true names of all the Neverborn tattooed in her skin", would that work?
2) For getting / skipping development of various technologies. Let's say Molly uses BMI and transforms into a random WH40K space marine, then lets herself be scanned and prodded via Court medicae. Would they be able to reverse engineer astartes enhancements?
Taking it further, let's say she imitates Wolverine or any other X-men (or, really, anyone with genetic based enhancements), and either lets Tiffany to touch her (I assume Lore of Flesh 5 allows her to also perform some manner of scans) or subjects herself to genetic analysis by the courts. Would the genetic enchantments (x gene, supersoldier formula, etc) be usable?
On one hand, it's a 5 dot charm, the pinnacle of celestial exalted might, powered by a nascent primordial who literally defines and creates her own reality. On the other hand, so many exploits... Some manner of balance is probably required.
Also, noticed an error in Molly's statsheet. Inner Devils Unchained is indicated as a 5 dot charm, but it's a 4 dot one (and we paid for it as such).