Hey there,
as a long time reader, rare time poster (over at rcz) I can only say how impressed I am with all those new Lazer part designs. I'd love to get my hands on those CAD files and ask around at local firms if someone would mill them for me

. But of course that won't happen

.
Regarding those designs and heat dissipation: Have you considered a finned design like on this Lazer I once have seen in an ebay auction?
One could also raise the rear top deck connection base and bolt the top deck bottom up like this:
This would increase the connected area between the fins and the top deck mount and "increase the space" below the top deck for bigger non saddle-pack lipos, since you could push them a little bit farther to the rear end.
Of course it would be annoying to assemble into the car and you'd have to consider different upper deck thicknesses. Last but not least Welshy's belt tensioner design would have to be changed, but hey, it would be more blue aluminium
Another question: Did anyone ever considered 3d printing to create some spare parts? There are quite some shops which offer Nylon 12 as material, which might be good enough, at least for some front bumpers or maybe some C-hubs.
so long
sz3