Dave, you are right. It is against the ethos to charge for downloads at all and we do believe that we add value to our users and donations will allow us to keep the site going. Having a “forced donation” when someone reaches a certain limit is something we do not like.
Since 99% of our users do not reach the technical download limit anyway, we decided to leave it how it is for now and those who do reach the limit can contact us and let us know. We have means to extend the limit individually.