How can I bypass my spousal stuff and come back to it at a later point in the process?

You can put in an estimate for now and then enter the correct amount before you file.

Line 23400 less Line 23500 equals Line 23600. So, if your spouse didn't have any social benefit repayments, then Line 23400 is the same as Line 23600. Line 23400 is not on the detailed summary; you will see it on your T1.