I have the same question. Does anyone have an answer for this?
What you can do is put your script on the click event of a regular button. When you are satisfied with the state of the form, you can invoke the click event of the submit button programmatically.
if (no more validation) then
For workspace, I add the process fields which includes the submit button. That submit button is then rendered as a "Complete" button in workspace. I assume that I can add my script to that submit button, correct?
I'm assuming you talk about the visible 'Submit' button. This button is in fact a regular button that invokes a hidden submit button.
If it's the case, then yes you can add you script in there.