I am not saying im right or wrong but maybe a consideration and maybe someone with more knowledge would be able to answer this better, as it is a monocoque (Spelling) design would the sill not be structual to the car? Or is the sill part just to hide the main structure behind it (for looks and aerodynamics)?
Maybe a body shop would be able to pull the dent out if necessary.
How did you manage it, if you don't mind me asking?