While I can clean out old shares from the core database, the webserver still requires a full history of shares for active servers.
That sounds like a pretty bad design flaw. So I have to assume it's more a case of using a product to perform a task it was never designed to do or even using it in a manner never envisioned by the developer.
No, we just never envisioned a pool server running on for months at the time. There were (multiple) plans to rewrite it by the original author and others, but nothing has come to fruit from them so far...