"Overwrite Dialog Box
This dialog box lets you specify whether the files of the active component (the component selected in the Setup Design or Components view) overwrite already-existing versions on the target system always, never, or conditionally based on date/time stamp or version number."
If the documentation had clearly indicated this dialog only appears in an InstallScript project, then I would not of wasted so much time on trying to hunt for it. As it stands, the opening description about component applies to InstallScript MSI project, Basic MSI project and InstallScript project; hence it is reasonably expected this dialog will be in all those types.
For example, the description for Operating Systems Dialog Box clearly indicates it is for InstallScript MSI project https://docs.flexera.com/installshield26helplib/helplibrary/IDlgScriptOS.htm
@roman2 <-Thank you!