That's roughly what we did: the T4 template work in combination with a cache that a) takes LINQ expression trees with invalid, though ITable-compliant, classes;

That's roughly what we did: the T4 template work in combination with a cache that a) takes LINQ expression trees with invalid, though ITable-compliant, classes; b) swaps out the ITable-compliant classes for LINQ to SQL's Table classes; c) compiles the expression tree into SQL; d) caches it, so we only have to pull this stunt once. The power of Microsoft's tools is that this is possible. The bane of them is that it was necessary in the first place.