I am going to be doing a 1040X for my 2020 taxes. Switching from MFJ to MFS. After I submit when does my spouse submit their new 1040? Right away?

I know that MFJ is usually more beneficial but this year due to stimulus money it makes way more sense for us to file separate. I just don't know when my spouse can submit their 1040 without causing confusion after I submit my 1040X.