Can you keep a brisket warm at 140 degrees in Anova oven you did not cook in it
If you’re just talking about holding it at temp, yes. I’d run some humidity, maybe 50% or so, but yes.
For what it’s worth, I would wrap a brisket in foil, then put that in a plastic bag, and wrap it all with towels in a cooler. I have kept brisk fresh and moist for 4 to 5 hours like this.
If smoked brisket, your oven will stink of smoke for weeks afterwards…