Sorry for writing it so convoluted, this is what the idea actually is.
- User optionally enters "fuckincheck0326" into a field the support page.
- Account number is updated to a new value that uses this value as a source of randomness.
- Newly generated number is provided on the check identically to the current flow.
- User is expected not to touch these values or settings until the check is processed.
- When the check is processed the user may opt to enter "@@april2026" into the field as in the first step, granting a new number to be used again.
- The user does not need to alter the value and can simply send a new check with the same number, but if the user enters a new value the old nunber is wiped out, and cannot be regenerated from the source code or any other records due to being sourced from user input.