Maybe I’ve been misleading by using the word “template”, sorry.
I personnaly don’t like working in PDE, as it’s not a very good code editor next to, let’s say, VSCode. My solution’s purpose is to work in your prefered editor with a single instance of PDE opened next to your editor.
With this setup, you just load the .pyde file in PDE, and clic on the “Play” button when you want to launch your sketch.