This will be annoying if I try to visually read out the microcode values since I'll need to examine each transistor closely. It was quick to read out the constant ROM since I just needed to glance to see if a transistor was present or not.
Here's a photo of a 7x5 region of the microcode ROM to help the discussion. The transistors (representing bits) are where the vertical polysilicon lines cross the pinkish doped silicon. Note that the "neck" is full-width, narrowed, very narrow, or entirely gone (no transistor), corresponding to the 4 values.
Image link: https://photos.app.goo.gl/pUsZSs3rx45Ry7U1A