Maybe it’s just me, but I find there’s definitely something about Starboard/Larboard that’s more difficult to reconcile mentally.
Tsukiyomi’s Bright/Dark blade went in far easier, thanks to Bright=Right, and now I automatically, reflexively recognise Dark as Left.
But this hasn’t happened for me with Larboard, I still need to consciously think “L for Left” instead of it being a reflex. Or Lardboard=Port, because I believe Port and Starboard would make far more sense to me personally.
It’s probably the length of the word. Left/Dark/Port are all 4 letter words, while Right/Bright/Starboard stand out as longer words. It’s much easier to take a mental snapshot of an entire word, than it is to pick out one letter in it.