Kudos to @TypoTonic for proposing this and @TryNinja for the script, but if I read the OP correctly, what he is suggesting is what will defeat the current Speed and Time of making the quote available for reply. But this one can't defeat the two. The OP's idea is something that will be highlighted directly from the post and a "quote" will pop up, just like your regular copy/paste pops up. Then by clicking it (the quote), it automatically paste itself in a way ready to be posted under without any extra work.
You understood this so well.
How it works:On the tech forum, the quoting system works in two slightly different ways depending on what you choose after highlighting text.
When you highlight a portion of a post, a small popup appears similar to the browser’s copy/paste prompt showing two options: “Quote” or “Reply.” Just as i explained above.
If you click “Quote”, the selected text is added to a separate quote collection page. All the excerpts you’ve selected are stored there in sequence. When composing your message, you can then click an “Insert Quotes” button in the message editor. This opens the collected excerpts, and you can insert any specific one into your post with a single click.
If you click “Reply” the highlighted section is immediately inserted into the message field as a formatted quote, ready for you to respond to directly. No full-post quoting or manual editing is required.
check img below.

@MarryWithBTC, could you please post the link to the SMF forum you mentioned, for practicality?
https://hardforum.com/forums/motherboards.4/ - you will need to pass verification.
admin: i am not promoting another forum, you can block this, if it is not allowed.