I've been testing with the latest source and I've found various issues with the -noflicker option.
All the following controls resize correctly, but the contents aren't visible until the user interacts with the control (say moving a scroll bar). The contents of the control is windows grey.
* Win32::GUI::Grid
* Win32::GUI::Scintilla
* RichEdit
The following controls resize correctly, and the contents are correct but the control still flickers.
* Win32::GUI::AxWindow
* Graphic control
I've had a look through the source - but didn't get anywhere. I can provide examples if needed.
Other than the issues, a great option. Nice work.