You never use multiline composer (called "Adobe Paragraph Composer" in Indesign)? That surprises me, as it is the default composer. So that means you are making a conscious decision to select "Adobe Single-line Composer" in your layouts. If you don't mind sharing, I feel I might have an opportunity to learn something I hadn't thought of before if you would tell why you prefer the single-line composer. I have always wondered why leave it as an option. For my part, this is a sample screenshot in InDesign from the Bible project I have been referring to, except this time I have set up side-by-side copies of the same column, once with the "Adobe Paragraph Composer" (what I referred to in my list above as multiline composer) and the more basic "Adobe Single-line Composer," which is analogous to the method Affinity Publisher is using. Other than the composer chosen, there is no other change to the two copies of text. The multiline (left) has a much more consistent spacing across the whole paragraph, while the single-line (right) has less consistent spacing and some really horrible gaps that would have to be dealt with manually (and then dealt with all over again at the slightest text reflow caused by editing or style change). It is this inconsistent spacing that I have been dealing with in Publisher, and truly, the lack of a multiline composer is my own greatest missed feature when using Publisher. Literally everything we do has justified body text, and almost always with multiple columns, therefore, more narrow columns where the difference is more noticeable. I have been doing it manually in our shorter publications, although I never like the result as well, and it does take me a not inconsiderable amount of extra time.