A bit of thinking out loud here-
I wonder if you could use a switch like this ?
It look's like it might work, it's pretty compact and only cost's $4.70 inc delivery!
I'm guessing that the switch set up is semi waterproof due to it being for a motorcycle too
7 8" ATV Bike Motorcycle Scooter Offroad Horn Turn Signals on Off Light Switch | eBay
Wire Setup:
Blue : Lights
White: Horn
Green: Right Turn Signal
Yellow: Left Turn Signal
Red: Ground for Turn Signal Lights
To wire it up to use as a 3 option timing selector, and a kill switch
Use the indicator's L/R for map 2, and map 3
Run the green from the cdi box to the red on the switch as an earth
Then run the yellow from cdi for map 2, to the yellow on the indicator switch (left turn)
And the white from the cdi for map 3, to the green on the indicator switch (right turn)
The green from the cdi could be ran through the light switch (red on/off button) to the blue, then the other blue join's the red wire (earth for indicator's/2 map setting's)
Then with the 2x remaining white wire's (for the momentary closed horn switch) you could connect them up to the black w/white striped wire from your original kill switch and the other white to the green from your original kill switchs' earth
The green button is your kill switch,
The red button is the timing control main on/off switch, it switch's on your earth for the cdi timing map's, allowing you to select map 2 (via left indicator)or map 3 (via right indicator)