How does the review request on Patreon work?

I’m a bit of a newer fan of Linkara, and I’m genuinely interested in his review request Patreon reward, but even though I’ve read over the details countless times, I’m still not super clear on something. He says, “Requests can only be made once every two years.” Does this mean each individual can only make a request every two years, or does he only make a request video once every two years?