Qie Lei

In the default Gutenberg visual editor, multiple spaces you enter are often “merged” and cannot be seen. This plugin solves this problem by converting consecutive spaces to HTML   entities, preserving the visual spacing.
Features: 
– Converts second and subsequent spaces in a sequence to   entities 
– First space remains a regular space (Gutenberg default behavior) 
– Works anywhere in the content, not just at paragraph starts 
– Option to apply to all content or only new content 
– Preserves spaces within pre/code blocks
<ul>
<li>Author’s blog: https://www.qielei.com</li>
<li>Improvement suggestions or problem feedback: qielei@gmail.com</li>
</ul>

Real Editor Space

Preserves real spaces in WordPress Gutenberg editor by converting multiple spaces to   entities.

kb_unhammer

This is a very simple plugin for the default (TinyMCE) editor. It adds 
a button that puts in a paragraph which won’t get deleted by the 
linebreak-eater (the one that starts munching when you press 
“Publish”).

Empty Paragraph for TinyMCE Editor

Adds an editor button that puts in an empty paragraph which won't get deleted when you save.

Real Editor Space vs Empty Paragraph for TinyMCE Editor