I’ve got 2x ESP32 and 2 group of 9 LED strips (see picture).
As WLED specialist what variant [A/B] would you use for cabling (signal cable only)? Variant C I won’t use.
How long is the distance in case C? The output from a LED pixel can’t drive longer distances, but with a non inverted booster (2 inverters in chain) it should work. “Gold standard” is use RS485 gateway - up to 500 meters possible 
I use exact this in my last project: https://wled.discourse.group/t/ws2814-based-power-led-pixel/9869
My LED strips are around 0.5 - 2m only.
keeping the data lines short is best. Y-splitting the data line to multiple strips is also not a good idea if that is what you planned, it can lead to flickering.
This is not an Y-splitting. I will connect 9 signal cable to each esp32. My question is: “…what is better/best cabling for easyer programing esp32 later” in following situation (see picture).
that entirely depends on what animations you want to do but you need the same amount of mapping for both situations.
“…same amount of mapping for both situations” - exactly this information I’ve got needed - thanks a lot!
there is the “create a segment per output” option that will create default mapping