I am not sure why a title company would require an ILC. As I recall there are three difference things, an improvement location certificate, an Improvement Survey Plat, and a real survey (ALTA). The ILC is just a sketch of the lot as platted and no measure anything, hence it won't resolve boundary disputes or anything else.

An ALTA survey is someone comes out and checks the pins and measurements, it is also expensive. An ILC should only run about $150.00.

If you look at the contract, the standard title policy does not insure survey issues such as encroachments. Also make the buyer pay for it.