I’d really love it if there was a pref for setting it so all scripts would open with line wrap on.
You can configure any View settings using the Window > Save Window Size & State command.
First, create a new document and configure it as you want for line wrapping, show invisibles, etc. Alternatively, open an existing document which is configured as you want. Then issue the Window > Save Window Size & State command.
From this point onward, newly created documents will inherit these settings.
NOTE: content related preferences are handled by script templates.
Well I’ll be dipped. I wonder how many times I’ve opened the Window menu and failed to realize those menu items were in it. Thanks for describing which things it affects.
I would like this also, independent of the “Save State” command.
What about all of my existing scripts?
Can I cause them to open with line wrap enabled?
No, this is a per-document setting. You could try and script it in some way by setting the document's wrap lines property to true.
I’ve looked for some sort of line wrap mode switch in Script Debugger Preferences but so far not found anything. Where can this be turned on and off. Once it’s on, I understand about using the menu item “Window/Set Default Script Size & State”, but don’t see how/where to turn it on to begin with. Thanks…
Please see the Wrap Lines item in Script Debugger’s View menu.
I found it - it’s an icon above the scroll bar - just click it to toggle line wrap mode. Found it in the Help file for Script Debugger … that probably would have been a good place to start looking before posting a question here I guess 
So fun to be a noobee.
Really like use Script Debugger so far. But reading about the security problems that Mojave and newer macOS versions will have with Script Debugger and other non-AppStore apps, wonder if Apple is slowly killing off the ability for people to create software for their own use, rather than develop it for AppStore. What is the long term future look like for Script Debugger??
Thanks…