As Adrian wrote, globally resizing the model is not a big issue.
The problem is with the assembly slots. Their width has to match the material thickness. That's why the models are delivered for several standard material thickness.
If you resize the model, you'll have to edit the vectors to manually resize the slots according to your material thickness.
Of course, depending on the model, you may also have other dimensional issues. If your model only uses crossed parts (as a dinosaur skeleton), slots are the only issue. But if you're stacking several parts of material, you may not be proportional according to the stacking axis as the material thickness dictates the size of the stack.
I hope it was clear enough.
W7 - Aspire 8.517