You can open a separate reply window in your browser and copy & paste the quoted text/reply HTML from the other window. If I respond to multiple
people that is what I do. Use the preview feature to check on how it looks before posting.
If I want to reply/quote several people, I click the appropriate link on their post, then copy/paste the results to a text editor. Then I add whatever
comments I want to make and paste it all into a separate reply post. I always preview first to make any adjustments.