The 2DM860H chinese controllers vs the rest?

[Neale]

I would read the data sheet and set the current to something reasonable. That is science.

Once the machine is running, adjust it so that the motors run at a temperature that is just about as hot as you can comfortably hold, which is around 60C. That is engineering...

Seriously, stepper motors are designed to run hotter than you might expect. More current gives better performance as long as you do not overheat them. Those current readings are really only a guide or a rough starting point, not absolute limits. Remember to set the stationary holding current to half (usually a dip switch setting) which helps keep them a little cooler while not moving.