There is no "with" info in the debug info. (dwarf has it, fpc does not use it / fpdebug hence doesn't have it yet either).
IIRC, some variables work in "with" blocks, because codetools gets a go at it first. (but I may be mistaken).
If I am not mistaken, then it needs to be dealt with in codetools. (i.e. not something I (usually) work on / but something that can be done...)