Coax pitch and roll servo travel very limited

[vgrsystems]

Using px4 firmware with a pixhawk2/cube hardware with qgroundcontrol and developpping a coaxial drone, I found that pitch and roll servos have a very short travel course (20°deg max) even at full pitch/roll RC. As a consequence, the drone doesn't fight the wind well.
Is there a way to increase the servo travel? I would like to move the servo at least with a travel of -45deg +45deg.
Thank you very much,

[vgrsystems]

EDIT: for coax, servo travel can be adjust by increase the ROLL_RATE_LIMIT & PITCH_RATE_LIMIT from 220 to the max 1800DEG/S