The Quote Editor has one requirement to work. You have to add the citation link before moving on. I usually add it first before adding the quote.
It doesn’t have this requirement if you copy a post that has a Quote Block before the new editor was added. Simply replace the quoted text in place of the old text. I always used a link to the original article even before the new editor was added.
This makes it easier in some ways. I created a template as tables can be a pain to replace in a Quote Block.
Where I noticed an issue is if you add a list in a Quote Block. It doesn’t matter if bullet points or numbered list. It posts it as a regular text block. A solution is to either copy/paste in Notepad or a similar program, then copy it from Notepad to WordPress. At that point, you can number it by placing a number in front of each item.
It’s a pain and sometimes I leave it as copied instead of adding numbers.