you should know that :
0- Joy4Bve has be only tested with bve 2.4.12 version.
1-joy4bve never know the levers state in BVE (not a problem actually).
2-You have to use the first option keyboard  in BVE
3-When joy4bve is in neutral state you can choice the mode,  brakes  or throttle.
4-When joy4bve enter in neutral state you should ear a short sound like "clack"
   (there no visual neutral indicator for know).
5-Every time you change to a highter absolute zone you should ear a short sound like "tuk".(if you do this quickly sound will queued). 
ej  +1 -->+3  you ear two"tuk".  0(center) --> -3  you ear 3"tuk"  .-4 --> -2 nothing.
6-Joystick have to be well calibrated via control panel of windows

With this knowledge we begin with the next scenario with cl158.
For testing  let's the Bve cl158 train  in all neutral with keyboard:
 no gear (no Forward no backward), no throttle, no brakes if  track has no gradient the train will no move.
if joy4bve is not started ,start it now the program should begin in neutral state with this default setting
throttle axis :   y     (you cannot change this option in 00_00_04 version)
brake axis :  y       (you cannot change this option in 00_00_04 version)
throttle notches :1
brakes notches : 1
control_type :  "train has unified brakes-throttle"
anti panic slider : 500  (for know  500 is OK)

Now with cl158 train change settings like this:
throttle notches =  4
brakes notches = 3
control_type = "train has separate brakes throttle"
anti panic slider = 500  (don't change)

when you change setting the debug window of Joy4bve will reflect this.

We suppose that Joy4Bve is in neutral state(  last sound  ear  "clack"or joy4bve just started ok).
*Now click the debug windows of Joy4bve

[braking mode]
from neutral state
* move slowly joystick lever top up ,
        (this change the state of Joy4Bve in brake mode and apply brakes )
        you should see three "." in this window and ear three "tuk"
*release slowly joystick lever to center , nothing will change
*move slowly joystick lever top down ,
        you should see three "," in this window and ear three "tuk"
*release slowly joystick lever to center
        you should ear one "clack" the "clack" mean that joy4Bve has enter in [neutral state]

(from neutral state yo can go to throttle mode or brake mode)

[throttle mode]
  from neutral state
* move slowly joystick lever top down ,
       (this change the state of Joy4Bve in throttle mode and increase throttle )
        you should see four "z" in this window and ear four "tuk"
 *release slowly joystick lever to center , nothing will change
*move slowly joystick lever top up ,
        you should see four "a" in this window and ear four "tuk"
*release slowly joystick lever to center,
        you should ear one "clack" the "clack" mean that joy4Bve has enter in [neutral state]

notes and tips :
1- to change the mode, the last sound you ear ,have to be "clack"
2- there is by-pass  for change from full release  throttle(top up joystick lever in throttle mode)
    to apply full brake that can be set with anti-panic  slider.
3--if the setting of Joy4bve is OK with selected train in bve  you can apply and release
    several times, throttle and brakes ,moving  joystick lever  and all will be synchronized
4-there no obligation to apply or release, full throttle or brakes ,you can  go step by  step
    and release  joystick lever between steps 
5-if you change of train change bve setting accordingly

If all is OK put Joy4Bve in neutral state and click or focus BVE and test with it
once you feel comfortable with it try to ride (engage forward gear in BVE) .