I guess I don't consider it a big deal or a separate set of books. It's just a form. I have the PDF copy as proof I filed an extension. It asks for 2 figures from taxes. If you owe, then you do have to go back into the desktop version and add that payment. Nothing else is done in the online version. If I recall, if you select the option to do it in desktop, it only has you print the form, but it reminds you to enter any payments. If doing the extension on the website, you have to remember to add those payments. I agree though that it seems odd not to have the electronic filing option in desktop. However, to me it's not a big deal to spend 3 minutes to file it online. In fact, I just did it for my sister's taxes I am filing for her for the first time this year.
