I understand the overuse notification is tedious, and it's also tedious for me, but unfortunately the problem is that some people launch web scrapers (web robots) on the site and download huge numbers of pages, so it's necessary to limit use. Before I instituted this system, there were instances of people downloading literally gigabytes of data from the site, causing substantial running cost increases.
I'm thinking about using a CAPTCHA instead of the current system. I'll try to implement this so that you stop getting the messages. Thanks for letting me know about your concerns.
Since this question often comes up, I've added it to the FAQ-FAQ here:
Thanks Fiona.