I don’t know what you mean about the MAX able to be serialized. Are you saying that several 7 segment 6 digit displays for example, can be daisy chained?
Found these from propwash which might cover up what would likely be horrible square holes that I will make.
I can’t find any 5 digit 7 segment LED though, so I am hoping a 6 digit 7 segment LED would fit (with one digit covered ).