We do not provide 100% reply rate percentages for connected inboxes since this type of activity can cause issues overall during the warmup process since that type of activity doesn't fall in line with the average use behavior/email activity of an email address so overall that can damage the sender reputation.
On a free trial, the maximum reply rate is 25%. With the paid Basic plan the maximum reply rate is 25% as well, with the Pro plan, it´s 45%, and with the MAX plan it´s 65%.