You should use in-place version of the jump combined with physics to jump without root motion. You should only use root motion jumping with physics turned off during the time of jumping. You don’t have to split the beginning and the very long middle section of the jump animation, since one should always be exactly the same amount of time after another. Only transitioning to landing animation time is a variable.
If you run out of the “jump start” animation, blend to falling loop to continue the motion.