Not so fast, I think this is a real issue. And you should not disable the flag "Heated bed", unless your printer really has no heated bed! If you do that Cura will not automatically insert any G-codes to control bed temperature.
See my screenshot, Cura is inserting my "initial layer bed temperature" before my own start G-code settings, and since I use "material_bed_temperature" for automatic bed levelling, that "initial layer bed temperature" is effectively overridden. It correctly inserts "material bed temperature" after the initial layer further down in the code, but since it insists on inserting code before my start g-code it really messes up the first layer bed temperature.
Why is cura doing this, and can this be changed?
IMHO it should not insert *anything* (except comments maybe) before my own "start G-code".
I guess I could workaround this by using material_bed_temperature_layer_0 for my bed levelling, but I really think this behavior needs to be changed.