During the downtown loft conversion, the team used thinner mud to speed things up. Big mistake, because the walls cracked after the paint dried. Specs are not random rules, they are based on what works. Pressure to finish is normal, but fixing errors wastes more time. I would never agree to cut corners on material thickness. It always comes back to bite you.
Had a client insist on skipping the primer to save time... the paint peeled in under a year. Now I always explain why each step matters, even if it slows us down. Shortcuts just don't hold up.