Debugger can be configured in SDK setting dialog (File->Project Structure->SDKs).
I-Pascal debugger will show variable values during debugging as usual: in variables view and when mouse stops over a variable in code editor.
Pascal-specific types are supported: strings, dynamic arrays, open arrays etc. When applicable, additional information is displayed: length, reference counter, code page for ansistrings.
IDEA inline values are also supported. Mouse hover and inline values can be configured in File->Settings->Build, Execution, Deployment->Debugger->Data Views