Tom;

The OP was comparing developer A to developer B and referred to film. If you use one developer and one film, you may see what you refer to as temperature varies.

Consider the attached chart which I am reposting. Note that the slopes of the developers vary greatly and some are even the reverse of others.

This may completely upset things if you move across this set of developers. Note the DK-50 in particular, and how it has a vastly different slope than the other developers.

PE