4

If you click the quote button in a way that opens a new tab you could go down the list of people you wanted to quote, opening each in a new tab.
The quoted section is in your Add new comment box, and as Raccoon City said, copy/paste from each subsequent tab and putting them in the original tab you opened them from.
Or you could do a cumulative deal where you hit the quote button to reply, copy the formatted text from the Add new comment box, then go back.
When you see another post you want to reply to, hit the quote button again, insert the text you have in your clipboard before the formatted quote in the new box, select all and copy to clipboard.
Just keep doing this until you’re ready to answer them all.
OTOH, that method has a huge point of failure, probably best top open new tabs to all the comments you want to reply to.
lotta work.