The following example creates so many lines of messages about fonts in the log.
fonts > 'fallback modern-designsize rm 12pt' is loaded
fonts > defining > font 'notoserifcjkkrregular', feature 'vert', script 'grek', no language 'kor'
fonts > defining > font 'notoserifcjkkrregular', feature 'vert', script 'latn', no language 'kor'
fonts > defining > font 'notoserifcjkkrregular', feature 'vert', script 'kana', no language 'kor'
fonts > defining > font 'notoserifcjkkrregular', feature 'vert', script 'cyrl', no language 'kor'
fonts > defining > font 'notoserifcjkkrregular', feature 'vert', script 'dflt', no language 'kor'
fonts > defining > f
...
Of course, there is no problem to get the output.