When to form a Solo 401k: before, or after leaving a W2 job?

[Veronica Ivy]

Hi y'all. I'm about to leave my W2 position and basically be a full time professional real estate investor. I am super sold on the benefits of rolling over my 401k into a Solo 401k and then buying rentals with it.

My question is, the end of my work contract is May 15. I want to be able to put offers on properties asap. I know the rollover will take time. Should I set up the Solo 401k NOW before I leave my W2 employment? Or should I wait until immediately after I leave my job?