Legal title is often irrelevant, when community-property questions arise in a divorce or probate context.  Are the expenses paid with community funds?  Does the income go into community accounts?  Were the spouses married when the properties were bought?  Even for tax returns, you might have to sort those out.  

If separate returns are being filed to avoid the California millionaire tax, expect the FTB to look at substance as well as form.  As for how to get Lacerte to do the split, someone here might have suggestions or a solution.