checkout/confirmation email help please

We use Authorize Net and are aware that Universal email will not work as usual, that it needs different set up in order to send confirmation email and copy to us.

I found Jason's help to someone in the forum stating :
"when using a remote checkout method, you cannot send the email from the confirm page when the confirm page posts, the email must be sent from the checkout success page instead. This is because the form on the confirm page is set to post directly to the remote payment gateway server.
You will need to add a set session value server behavior to the confirm page. Set the trigger to any form post, the name to "EmailAddress". For the value, click the lightning bolt, and select the Email address form element.
Now add the universal email behavior to the checkout success page, use the EmailAddress session variable for the from address and set the trigger to before page load."

MY QUESTION today is: checkout success page is not used, as far as I understand since Authorize net sends their own. Will the above solution work anyway? I am just hesitating to edit our cart now that all else is working fine.

it is the one item we still need to solve for our cart. We would like to receive a copy of the email with the order/details . As things are now we would have to log into the db , to get 'all the details' everytime someone makes a purchase.

I really appreciate your help !