whoot. team
Most of what goes wrong is seen by someone with no way to tell you.
Every site has a reporting gap. Staff have a radio, a room and a supervisor. Everybody else has nothing: contractors, visitors, delivery drivers, stallholders, the crowd. On the days that matter most they outnumber your team by a wide margin, and they are the ones standing next to the problem.
The usual answer is a generic email address on a sign, which works about as well as you would expect. Nobody has their laptop, nobody remembers the address, and what does arrive is a paragraph of prose that somebody has to read, interpret, chase and remember to close. A reporting channel that costs effort to use gets used after the fact, by which point it has stopped being a report and become an incident review.
So reporting now lives on the page you already point people at. The QR sign-up link that puts somebody on your alert list can carry a second, entirely independent section: Report an issue. Scan the code, answer your questions, send.
The two halves of that page do not depend on each other in either direction. Somebody who never enters a phone number can still report. Somebody who signed up ten minutes ago can report without doing it again. And when the recipient list behind the link reaches the end of its date window and stops taking sign-ups, reporting carries on regardless. A list window decides who gets texted. It has no business deciding whether a hazard can be reported.