We're still using version 2 so not sure if this will help you but, but there is a check box at the bottom left corner of the "printing plates" section of the wizard. You can un-check it and then set an offset value.
I am not sure how to turn off the auto check box but there are a couple of ideas that might work. First you can play with the Plate Template Editor and ad .625 to the Baseline value. However this moves that gripper margin too so that may or may not work for you.
The other way is what I use a lot for custom setups or very common setups. And that is with Job Templates. When your in the Job Assistant you can get there by the icon in the top right "Jobs from Template." To save a job in the "Job Templates" area you can right click on the "Jobs" icon under the Product Parts tab. Then Save job as "Resource Job/Templates." Then every time you need a particular plate setup choose the appropriate Template. Just set the job up the way you want before you save as.
Hope this may help