plausible, but my experience from dissecting these kinds of games is that they tend not to be as space efficient as you’d think they could be if they were the kaze emanuar type. The fact that they opted to have 257 distinct values for the laurels suggests to me that they weren’t prioritizing space efficiency.
My best (wildly speculative) guess is that a designer, knowing 256 is a common limit, wasn’t thinking carefully and said the maximum value should be 256 (instead of 255), and then an overly pedantic coder implemented this to the letter while rolling their eyes.
I’ve never given TGL a proper listen, though I have the game for NES. Thanks for the recommendation!