I like the direction you took, but I'd double check that Generate Rows tool in your workflow. You have it configured to a Byte, but would want it to be at least an Int32 data type, otherwise you're not generating all the rows.
If using the RegEx formulas in the tool, you simplify the regex code like this:
Good catch, kind sir! I'm guessing I was able to match the results because none of flagged cases were above 255. Thanks for the insight, I really appreciate it. I've been using the Bytes a bit too aggressively, trying to make my workflows smaller. I will need to watch out for that. 😁