Compiling master (d8fc9979130a268cf55b12c223b20fd7d4b9f67f) on macOS Catalina (with a patch from #16720) reveals one more instance of QFontMetrics::width() which is supposed to be replaced with TextWidth() in the merged #16701.
Sorry for incomplete solution provided in #16701. It’s especially sad that the line I missed lies in only 7 lines from the code touched in #16701.