What is the command-line parameter to prevent Crash Recovery dialog?
I've tried noscwarning , but this did not work.

Supplying commandfile does not prevent the dialog either.

The ideal workflow I aim is to keep the dialog when starting the app in "GUI" usage mode
and to skip the dialog when executing script (supplied via commandfile) in order to automate tasks.

There is no parameter for this. You can only temporarily rename the recovery directory to prevent that PL/SQL Developer finds a recovery.

The recovery directory is located at %APPDATA%\PLSQL Developer [version]\PLS-Recovery

For example:

C:\Users\<User>\AppData\Roaming\PLSQL Developer 15\PLS-Recovery

Is it possible to add the functionality - skip the Crash Recovery Dlg - as a part of noscwarning param?

IMO adding a new cli param will flood the params, but you can arrange all dialogs preventing direct work after app start under the existing noscwarning?

I have added this to the list of enhancement requests for version 16.0.

10x

We have added a NoCrashRecovery command-line parameter for 16.0.

I was notified that the NoLoadDesktop parameter should already skip crash recovery.