https://www.merriam-webster.com/words-at-play/we-know-youre-concerned-about-important-and-importantly

Many people complain about use of the adverb 'importantly,' claiming that constructions like 'more important' are grammatically correct, but 'more importantly' is ...

https://english.stackexchange.com/q/229517

Feb 20, 2015 ... It seems that this prohibition was enforced until the 1940's when more importantly started to break out of the prescriptive box. By the turn of the ...

https://www.grammarbook.com/homonyms/more-importantly-most-importantly.asp

More Importantly and Most Importantly, commonly confused words in the English language.

https://www.ldoceonline.com/dictionary/importantly

importantly meaning, definition, what is importantly: used to show that your next statement or...: Learn more.

https://www.quora.com/Which-one-is-grammatically-correct-more-importantly-or-more-important

Either is correct, depending on the context. “More important” describes a noun, stated or implied, so “Health is more important than wealth”, ...

https://www.quickanddirtytips.com/education/grammar/important-or-importantly

Aug 24, 2017 ... You may occasionally hear or read an objection to the phrase “more importantly.” You can ignore it (unless you are writing a cover letter or ...

https://www.grammarphobia.com/blog/2019/01/important-importantly.html

Jan 11, 2019 ... Q: It seems to me that a majority of radio and television pundits use “most important” where I would use “most importantly.” Would you please ...

https://www.chronicle.com/blogs/linguafranca/2013/05/22/more-importantly/

May 22, 2013 ... We can start a sentence with More importantly, … or More important, …; but if we take away the more because the situation is not comparative, ...

https://brians.wsu.edu/2016/05/25/more-importantly/

May 25, 2016 ... When speakers are trying to impress audiences with their rhetoric, they often seem to feel that the extra syllable in “importantly” lends weight to ...

https://forum.wordreference.com/threads/how-to-use-comma-around-but-more-importantly.2761928/

Hi custner, your use of commas around "but more importantly" is right, but more importantly, your first sentence sounds a little clumsy because it ...