FWIW, i've definitely encountered code using some of std's Debug in ways which definitely wouldn't be caught out by miri or any form of static analysis, typically this took the form of relying upon String/slices, etc to be usable in ways similar to this internals discussion Repr formatter with ShowRepr trait generating rust source code strings, from string values. If it was just strings, escape_debug would be an option here.
The problem with attempting static analysis of this is that the Debug output is only being parsed in a separate process. In this case the Debug output was being sent back to the rust compiler itself, I've managed to remove most of this, from the project except for some opaque types where we currently lack any trait bounds that would allow us to do anything else.
And FWIW, before I get dog-piled macros aren't really an option for the project in question the input isn't rust source code, source code generation are actually entirely optional.