Manifold heat cross over physics and benifits

I'm convinced manifold heat is only really important for cold driveability and associated quicker warmup in cold climate. I struggled for years getting my 440 to run right during the summer where it would constantly be suffering the carb boiling and hard starting issues associated with heat and ethanol in the fuel. The thing that finally cured it was new intake manifold gaskets with the crossovers blocked. It's a little longer to idle right until 10-15 minutes or so after startup, but then again it always was.

That was the only difference apart from curing the main problems(s).