Yes, we're aware of this issue. Any address with more than 100'000 transactions are currently not working.
Unfortunately, we haven't spent so much ressources so far to handle that issue. We are working on a new internal system that will give soon, the basic info for every single addresses. As a first step, that still won't allow searching in "heavy" addresses. Then, we have some ways to improve the rest. Anyway there are lot of corner cases which are not easy to solve.
Any particular reason off-the-shelf tools such as Coinbase's
Toshi or Bitpay's
Insight are not suited to your use-case? They happily allow that kind of query right away and run fine on an average computer.