I found an apparent minor error in your datasheets for the MAX7300 and MAX7301 (https://www.analog.com/media/en/technical-documentation/data-sheets/MAX7301.pdf) you might want to correct in their next revision.
MAX7300 figure 10 on page 17, and the corresponding MAX7301 figure 5 on page 12, both show a peculiar (AND-OR?) gate symbol (flat on input side, pointy on output side) with inputs from Mask Register bits. They're clearly intended to be AND gates (round end, not pointy). Although it's obvious, you might want to tidy up the diagram.
Thanks for making cool stuff, by the way! :-)