Flasks overnight burnout cycle

I steam dewax my flasks before burnout, but would like to use my
programmable kiln so I can have them ready to cast the next morning.
I use an 8 hour burnout, but since I have to put the flasks in a 300
degree oven after steaming, I will need to extend that time
overnight. Would it be better to extend the time on the 300 degree
end, or just keep them at casting temp for a longer period of
time–or does it matter? Anybody else have a better suggestion?