Can I enter jointly owned T-Slips with someone other than a spouse using the % of ownership option and then override the default spousal % to zero?

I have dozens of T-Slips regarding joint ownership of investments (T5, T3, T5013, T5008 as well as Trade Receipts, Capital Gains/Losses and Rental Income etc) with a person other than a spouse?   Doing all of the % calculations manually for both of us would take hours and opens the door to mistakes.  Assuming I can use the % option with the override to spouse set to zero... will TurboTax accurately divide up all carry forwards by the % indicated?