And for the normal person. Positive (source) trigger or Negative (sink) trigger. lol.
Either is fine.
But remember most common SPST On/Off switches need the switched line to be 12v positive for the LED backlights to work.
Therefore most everyone runs the sourcing method.
I have moded a few common SPST switches for reverse polarity allowing the switch and backlights to work off negative for a few mods. such as 700 and 500 fan overrides which uses a sink method to operate.