Q: What range can I set?
A: 1–255 (clamped). 255 is the practical maximum for a VARCHAR(255).
Q: Do I have to run the schema job every time?
A: Run it whenever you change the option and want the DB column to match immediately. (Entity/form honor the option instantly; the job updates the DB column.)
Q: Can I reduce the max later?
A: Yes, but MySQL will truncate values beyond the new size when altering the column. Consider auditing long tag lines first.