Notice the 'w-[section name]' at the end. I mistakenly wrote 'w-[page URL name]' first.
About the number of substitution docs: If you follow this pattern, you will need 2 substitution docs for each section on the website, but you don't need subst. for categories, as they are handled by the generic category level substitutions.
So this is what is needed for each section name, fx. for the section 'accountingsoftware':