To be honest, the lasers take up most of the baeplate space as it is, so it may not be that much difference.rather than tec the whole base plate why not mount the lasers on a separate smaller plate and tec that?
I'm using 506 scanners so they're small and [maybe] the small digi amp.
And even then, the smaller plate means the hot side of the tec will be in the laser/optic deck anyway.
One thing to note, I think you said in the other thread you use a very thick (40mm was it?? or am i remembering/reading wrong?) baseplate. In my case it is a LOT thinner, so less metal mass, and so maybe easier to cool effectively.
P.S. what are you charging for the LCD/controller?