Please Note: Filing for and suspending your retirement benefit is not the same as or a part of restricting your application to your spousal benefit only and it is important not to conflate these mutually exclusive procedures: if you do one, you can't do the other.
Filing a restricted application, also known as restricting an application, simply means filing for only one benefit when you're eligible for more than just that one benefit. A common example is when one spouse files for their spousal benefit only, often at their full retirement age (FRA), and delays filing for their retirement benefit, often until 70.
No one can restrict their application to their spousal benefit only before their full retirement age (FRA). Further, due to the Bipartisan Budget Act of 2015, no one born on or after 1/2/1954 can ever restrict their application to their spousal benefit only, even at or after their FRA.
Also note that no one can file for a spousal benefit before their current spouse files for their retirement benefit. Divorced individuals can however file for a divorced spousal benefit regardless of whether their ex has filed for their retirement benefit as long as both are at least 62 and have been divorced for at least two years. The two year requirement does not apply if the ex has filed for their retirement benefit.
If you are eligible to file a restricted application for a spousal or divorced spousal benefit under Social Security's rules and provisions, you can model doing so in your planned what-if dates.
Learn More: How do I model a restricted application?