Will maternally incubating make the female permanently mean or aggressive?

I read somewhere online that if you allow your female to maternally incubate that it will make her an aggressive snake. So, experienced breeders who have tried maternal incubation does it make the female mean the rest of her life?

Absolutely not. As soon as the egg scent is gone, the snake will go back to her normal, pre-lay behavior.

so does her behaviour change whilst incubating ?

i read an article about maternal incubation that said some snakes even feed during it but it didn't mention any change in character ?

In my experience, females may be more defensive (which is different than being aggressive) of her eggs. But that can vary between individual snakes, some can be quite mellow and others may continually strike if bothered. This usually only lasts during the period of maternal incubation, unless the female was already a defensive striker prior to even laying her eggs! Some females will also leave the eggs briefly to drink water or feed if offered food. Hope this helps!