Does every joint need to config COMP_FILE?

I have three axis, if every axis has a backlash, do i need to config COMP_FILE = file.extension for every joint.
it means joint 1 and joint 2 also need to add COMP_FILE = file.extension in ini?

If joint0, joint1, joint2 compensation density can be set separately , do we need to add these content below and add screwcomp0.dat, screwcomp1.dat, screwcomp1.dat this three files.

"COMP_FILE = screwcomp0.dat
COMP_FILE_TYPE = 0",

"COMP_FILE = screwcomp1.dat
COMP_FILE_TYPE = 0",

"COMP_FILE = screwcomp2.dat
COMP_FILE_TYPE = 0",


[JOINT_0]
TYPE = LINEAR
HOME = 0.000
MAX_VELOCITY = 5
MAX_ACCELERATION = 50.0
COMP_FILE = screwcomp0.dat
COMP_FILE_TYPE = 0
INPUT_SCALE = 4000
OUTPUT_SCALE = 1.000
FERROR = 0.050
MIN_FERROR = 0.010
MIN_LIMIT = -10.0
MAX_LIMIT = 10.0
HOME_OFFSET = 0.0
HOME_SEARCH_VEL = 20.0
HOME_LATCH_VEL = 20.0
HOME_USE_INDEX = NO
HOME_IGNORE_LIMITS = NO
HOME_SEQUENCE = 1
HOME_IS_SHARED = 1

[JOINT_1]
TYPE = LINEAR
HOME = 0.000
MAX_VELOCITY = 5
MAX_ACCELERATION = 50.0
COMP_FILE = screwcomp1.dat
COMP_FILE_TYPE = 0
INPUT_SCALE = 4000
OUTPUT_SCALE = 1.000
FERROR = 0.050
MIN_FERROR = 0.010
MIN_LIMIT = -10.0
MAX_LIMIT = 10.0
HOME_OFFSET = 0.0
HOME_SEARCH_VEL = 20.0
HOME_LATCH_VEL = 20.0
HOME_USE_INDEX = NO
HOME_IGNORE_LIMITS = NO
HOME_SEQUENCE = 1

[JOINT_2]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 5
MAX_ACCELERATION = 50.0
COMP_FILE = screwcomp2.dat
COMP_FILE_TYPE = 0
INPUT_SCALE = 4000
OUTPUT_SCALE = 1.000
MIN_LIMIT = -8.0

there is no compensation effect,why? I added comp_file as it is descripted in linuxcnc.org/docs/devel/html/config/ini-...t__lt_num_gt_section

don't work