Homing on x y z at the same time

[Ninobr]

Hello everyone
I'm creating a project with 3 stepper motors, controlled by Arduino with GRBL 1.1h installed, the motors move 3 micrometric screws.
The 3 screws are vertical pointing up and they hold an aluminum plate which must work horizontal.
The system works and now I added the limit switches to always start from the same position also to calibrate the horizontal alignment with a spirit level in order to correct for different height of the switches after homing.
I tried to enable the homing procedure but the sequence of motors in cycle 0 is the homing of the z axis, then in cycle 1 homing of the x and y axes.
This is correct for CNCs, but, in my case, I would need homing in cycle 0 of all the x, y, and z axes at the same time to avoid tilting of the plate during homing.
I didn't find information on the web and I tried to modify the GRBL config.h file by putting all the axes together,
#define HOMING_CYCLE_0 ((1<<Z_AXIS)|(1<<X_AXIS)|(1<<Y_AXIS))
but compiling GRBL gives an error, since this is an unusual case not foreseen.
I hope someone can help me solve this problem, thanks in advance
Nino