The modules fail irregularly, and yes, there should be a heat shield between the distributor and the crossover pipe. There is a shield under the coil, also.
Some of the module failures are caused by other issues. At the 35th, for example, an ICM was replaced 5 times in a few hundred miles, but the issue was not the ICM itself.
There can also be issues with the wiring and connector.
Just know that the ICM will eventually fail, and there is no guarantee that the new ICM is good.