I don't know answer 100% - but think likely they will accept signed in ink. (Keep in mind this form also used for electronic-only submissions)
How long ago did you submit? Have you received any correspondence since?
It is possible to update and submit via webform. If you do not have a file or temporary file number yet, you'll need to either get the temporary file number or provide as much info as possible to 'match' the paper file to your webform submission (UCI best if you already have). It may take them some time to respond and actually match/attach the webform submission, so unfortunately that would mean waiting to find out.
(Don't know about wisdom of submitting a completely new submission when previous has already been received)