I think it is not made entirely clear if there is a difference between the free and paid versions as far as the composer component goes. There is a link in your documentation to a page where this should be explained, but there is no specific information there. What I would like to know is whether the premium version offers the option to include a single post and if there are any styling controls (like changing the color of links or aligning it with the newsletter theme).
you’re totally right, from time to time we find some outdated doc pages, thanks for feedback, we will update them as soon as possible. About your question: the Extended Composer Blocks addon has a Single Post block available with styling options. Remember also that all our licenses come with a 30-day money back policy, so you can always try out our professional addons and decide later.