Starting a title with a number is a common scenario, as sections may be numbered. It is much less common for a paragraph to start with a number followed by a full stop unless the paragraph is intended to be a list item.
This issue is similar to hashtags at the start of a line vs atx-style headers without a space. As argued in that topic, requiring a space after a header marker makes the document look cleaner. Similarly, requiring a blank line (to end the preceding list) produces a cleaner looking document and would simultaneously solve @tremby’s issue.