what you could do in addition would need to install python script plugin and those four lines of code.

def callback_MODIFYATTEMPTRO(args):
    notepad.menuCommand(MENUCOMMAND.FILE_SAVEAS)

editor.clearCallbacks([SCINTILLANOTIFICATION.MODIFYATTEMPTRO])
editor.callback(callback_MODIFYATTEMPTRO, [SCINTILLANOTIFICATION.MODIFYATTEMPTRO])

What it does:
By registering the callback the script gets notified when you try to change a read only file and therefore calls
the file save as dialog. You can either create a script but than you need to run it every time you start npp or
you put the content into the startup.py of the python script plugin then it get called automatically every time
npp starts.

What needs to be done first is described here

Just in case that you haven’t installed python script plugin yet, I would propose to use the MSI package instead of using the plugin manager.

Cheers
Claudia
Cheers
Claudia