The plywood is 6mm (1/4″) from memory. There was no point in the process that needed heat or steam to bend the panels. That all went extremely easy for me. Maybe in extreme cold that would be required, but the epoxy couldn’t be used in the cold anyway.
The mold protects the panels quite nicely. You could damage it by dropping tools on it and the like, but that would only be aesthetic. I recall one person on this board did crack one plywood panel but the fix was pretty straightforward.
This aspect of the build really is nothing to worry about.