I'm confused, Grey. The inks won't press differently from each other. The folks using Durabrite and those using Claria are pressing at 375* for 30 seconds.
I have read posts where folks press at different temps from the standard 375*, but that is usually because something didn't work for them, like the shirt scorches, or something else funky. But which ink was used to print a transfer has never come up, in my reading, as a reason to change the press temperature. That does not make any sense.

Is there more to it that I don't understand, or he just said he printed with Claria so lower the temp?
I know for a fact people are pressing Claria successfully at 375* if that is the case. I hope this helps you out some.