It's good that you haven't stopped answering BTT users' questions in this thread.
However, none of the users who have been on the forum for a long time have written any objective information about your offer and in general about the kind of business you offer.
But you will ask any of those 3 clients of whom you are already ours to write and who, as follows from your statements, have already tried this offer.
In any case, 3.5% seems too tempting an offer to me. And usually this is what offers look like that contain unpredictable or deliberately hushed up business nuances.
In general, I advise you to continue after the feedback of a user who has tried your offer.