Feature Request: Calculate "Private bytes" of all selected process

[GitUser200607]

I have selected 10 processes of Firefox, but there is no way to display CALCULATED total size of memory, used by all Firefox processes. The parent Firefox.exe only displays its own private bytes usage. But it has 9 child processes and they using memory. Can you please add a feature to display in Status bar calculated total memory usage of SELECTED processes? For example, I select CMD.EXE, Firefox.EXE, Calc.EXE and in status bar shows calculated sum of Private bytes. I have tested it in PH3.0.1335 and there is still no such feature. Thank you!