I don't know Rspec well enough to know if this is easy or not. Honestly I can't even understand the current specs well enough to know if this is already being done. But bugs like MONGOID-3009 and MONGOID-3015 should not happen on a well-tested system like this. There are lots of tests that confirm things like basic relations are working properly. But apparently they're not being run with the identity map enabled.

The specs should be altered so that most if not all should be tested both with the identity map enabled and with it disabled.