Thanks DaveF. In addition to your findings I found contrary advice on Intuit’s own site:
https://turbotax.intuit.com/tax-tips/marriage/tax-tips-for-separated-couples/L6H4vr1nd
“Since the IRS honors the divorce laws of the states, where you live affects your options as well. In Texas, for example, you remain married from a tax perspective until your divorce is final, even though you're legally separated.”
Further, I confirmed this for Washington state:
What is a legal separation?
This type of court case can give you everything a divorce does, except for ending the marriage. You are still legally married.
https://www.washingtonlawhelp.org/files/C9D2EA3F-0350-D9AF-ACAE-BF37E9BC9FFA/attachments/7EC4C22A-2D...
Wish me luck filing jointly. An IRS audit can’t be worse than watching our institutions dissolve in real time. —G
