They cannot marry someone else, and if one of them dies, the inheritance laws that apply to married couples will still apply.
Having an order of separate maintenance and support is also not the same thing as being “separated” before filing for divorce.
A legal separation can also help protect you from being held responsible for your spouse's debt, liabilities, and taxes after the date of separation.
Unfortunately, not all states recognize a legal separation.
But, you can file for temporary orders when you file for divorce as a way to protect yourself until your divorce is finalized.In South Carolina, the only way to obtain a no-fault divorce is to first live separately for a year.