Show Cue System

I am a new user.
I configured all my devices on the demo show; audio and DMX. Took me an hour.
I then wanted to start a new show of my own so I created a new cue file.
It seems to have created a new device map.
That is despite me having used the same pre-filled "MSI" device map name on creating the new production that I thought the other one was called.
This confused me because I read that a device map is DEVICE specific.
So I had expected it to pick-up the same device map.
I tried a bit of old skool and renamed the old file to the same name as the new device map file (and renamed that _old).
I thought that would nicely bring-in all my configs and save me an hour doing this every time.
But it's not having it. When I load I get options all over the place.
There doesn't seem to be an option in the UI to LOAD a device map from a previous show; that's what I want.
In the absence of that, how do I re-use my device map from the last show/cue file to the new one?
My next approach is to load the old show, clear all the cues to nothing, try to resave it as a new show and then use that.
Is that a good idea?
Thanks in advance,
Rob, UK

So I tried deleting cues from the demo show but it got into a loop with this error below and deleting two because I think I broke it's referencing system and I had to use task manager to kill the app.

It seems to be that for every new show (i.e. each new cue file) I have recreate my entire device map by entering all my audio and fixtures and dmx channels again

It feels like I'm missing something here.

I re-opened the demo file fresh, it had my device mappings for audio, fixtures and DMX.
I used the option to Save as Device Map and gave it this name as per attached screenshots.
But when I look in the devmaps folder, there is no such file; the only file is a device map named like the show.
So where is it saving this new device map that I need to carry over to the new show?
This is the mystery

I have realised TEMPLATES is what I need. I have successfully created a template and it carried over my device mappings for audio, fixtures and DMX.

I truly do not understand device maps and how they work but maybe I will get my head around those one day.

Templates are definitely the best solution for your requirments, but also consider Import Devices from another SCS Cue File.