Hiring an engineer to finetooth comb blueprints for mistakes before construction will take nearly as much time as having an engineer draft them themselves. And they will be smart enough to not do something silly like putting the electrical panel on the back of the shower wall. If you just vibecode some blueprints and start construction without the comb you could lose way more than you saved with something as simple as pouring a support pillar or building a wall 2 inches off and having to tear it out later and rebuild.