Contact Inventables tech support - firstname.lastname@example.org . With a new installation, they should take care of you. I have a Shapeoko2 with a 300W DC spindle and it barely feels warm after cutting for over an hour.
I need to qualify my statement by saying I have the 48V 300W spindle that requires half the current (amps) of the 24V. The additional current draw might make your spindle get a bit hotter.