It's worth sending them a note asking, but I'd bet they'd prefer you remove, or at least disable, it. As the place is named, they really want focus on the front sight, particularly for the first level of classes. They're good at getting large groups of people up to speed on a particular shooting technique, so trying to keep everyone on the same baseline of fundamentals would probably be a priority for them...so they'll want you using your sights and not getting distracted by other aids and such.