In fact, you need to save an empty Drawing file, in which you have defined your basemap and your desired options.
You need to save it in . DRWDOT. When you open a new drawing, you'll only need to use this template file and you'll have the options set in that drawing template.
A . SLDDRT contains only the Basemap, not the Layout Template options. That's why you need to register in . DRWDOT, which is a template file. It works the same way for parts (. PRTDOT) and assemblies (. ASMDOT).
When you open a new file, you can choose between the different template files you have created, so you can choose the default ones or the ones you created yourself.
In absolute terms, you should have a .drwdot that contains the options etc. it must be without a background. Then you have .slddrt which will be your basemaps. That way, you change an option and all your new plans will have it without having to take all your DRWDOT. only one is enough but in the tree you have to remove the background plan.