Is there a downside to including investment income on Line 4e? Will this comeback to hurt my client in the future? The only reference I can think of is depreciation as something that can hurt someone that fails to utilize the expense when they have a home office / rental property. 

Line 4c has $30,000. If I put $30,000 on Line 4e then I save my client money but I want to understand the effects of what I put on Line 4e.