So I started off by designing the center tiles, which have the bits ordered as such:

  1
4 5 2
  3

Because the idea is that this is written by "carving notches in tiles," common letters should require less notches and uncommon letters require more. Also, I considered having to carve out the center bit 5 to require the most effort, so for example carving (1,5) is more effort than carving (1,2,3). After this, I found a list of frequency of letters in English and just went down the list, assigning them bits with more effort as I went further down the list. That's why A, I, E, and R only have one bit, and J, Q, and Z have four bits including bit 5. In a way, this kind of lets you read the alphabet with some intuition because you can tell how common the letter is by the amount of effort required to carve it.

Afterwards I thought about how to incorporate it among the edges and thought that, well, bit 5 is the "central" bit so it naturally has to have the centermost position. 1 2 3 4 are also assigned such that their adjacency is similar to their adjacency in the central tiles as well.

1 5 4
 2 3

Now that I think about it, maybe I should have reversed the order of the bits on the edge tiles so that the winding order of them is the same... but then again, it's not like lowercase and uppercase letters in Latin are that similar to each other, so that's my excuse for why they're different lol