Dunno about the mentioned modules, but Perl has built in support for stack/frame tracing.

It's also possible to hook a function to every subcall when run under the debugger.

I used this before but didn't remember the details anymore, but this looks good:

RE: (Debugging, Tracing, Trace, Instrumenting) Automatic tracing of my Perl code?

I think that's flexible enough for your intended support for test coverage of legacy code.