Single-hand keyboard with xmodmap

xmodmap.onehand-colemak

keycode 29 = j J g G
keycode 30 = l L p P
keycode 31 = u U f F
keycode 32 = y Y w W
keycode 33 = semicolon colon q Q
keycode 43 = h H d D
keycode 44 = n N t T
keycode 45 = e E s S
keycode 46 = i I r R
keycode 47 = o O a A
keycode 56 = b B b B
keycode 57 = k K v V
keycode 58 = m M c C
keycode 59 = comma less x X
keycode 60 = period greater z Z

keycode 108 = Mode_switch
keycode 65 = space space space space
keycode 135 = Alt_R

add Mod5 = space

Does it work for you? For me it does not.

# first switch from Neo layout (de neo) to US:
setxkbmap us
xmodmap xmodmap.onehand-colemak

After that the left side seems normal but the right side is not. jkl; is neio. Space has no special effect except that is does not repeat the space character when pressed long.

Do you have any idea? I would like to adopt Neo layout for one hand.