The pass through method is perfectly OK. You see, the errors caused by high temperature are opposite to those caused by low temperature, and in the end it works out.

But, being too low or to high can cause problems, as the process works by diffusion of developer in and DIR fragments out. This is fine tuned for each film and each chemical at the plant.

There are literally hundreds of tests to insure that you are getting the quality you deserve. I know what upsets the results. Bad temperature control is one of them.

But, do what works for you.