Would be interesting if there was a way to annotate a set of commits, like "commit ???? - ????: refactored A,B, and C" so you'd get the advantage of small commits and clearer messages.
This is what PRs are good for. Also, with my particular approach to commits, I always have at least one issue associated to a commit, and I'm always working on a particular branch associated to the issue. I pick an emoji that captures the issue/branch in a single concept, and I have that in my subject line. This is combined with my git commit template mechanism, and I like it. At a glance, I can see which commits belong together, and if I want to look at the whole, I go to the PR.
I think you can do that in a merge commit, sort of.
The more I think about it, the stranger a strong aversion to rewriting commit history for clarity is. In university if I did some math / physics calculation, I would often start, and once I got somewhere, make a clean copy of the successful work to have a concise and revised version.
Mostly fine to do it on a feature/PR branch also, in my opinion.
If those become long-lived with multiple people touching them (where history rewrites become peoblematic) you are not integrating continuously enough.
E.g. https://github.com/ibgib/ibgib/pull/180