Using the Keyboard Fonts dialog to change the size of the touch layout font has the unwanted side-effect of replacing all literal text with \u codepoints, causing readability to plummet (at least for humans like me). Here’s a sample of the diffs after changing only the font size:
This problem is present in Kmn Dev 13.0.111. I now see it was also present in 13.0.108.
Workaround: It’s possible to edit the font size directly in the code view of the touch layout without affecting the literal text.