After meeting the male member, I was asked to complete a survey. All the staff who helped me were wonderful, so I couldn’t choose just one. Would it be possible to add an option to select everyone?

This is more of a request than a question, so normally it wouldn’t be displayed. But since it doesn’t seem malicious, I suppose it’s okay to leave it up... Also, I think requests like this are better directed to the staff privately, such as via LINE. As for the main point, making it possible to select everyone wouldn’t be technically difficult—in fact, it would be quite easy. However, I think the point of this survey is that you choose one person. If you really want to get the message across, you could send the staff a LINE mentioning each person by name and saying something like, “They were all wonderful.” Staff members also appreciate women who say things like that, so I think writing a little thank-you message each time is a good strategy.