Two things about "making stuff at the lab". You still need a battery for each one, which is its own gate. And because your gauges will still run with each "action", you have an increasing chance of failure even if you've made something 10 times. At least, that's how it is with the current setup. Saving up batteries will not protect you from dying due to sleep deprivation or bursting. Especially since you can't use items while in the lab.
So I would say that if we have a chance at guaranteed checks when making stuff in the lab, it would require two conditions. 1st: You've made that product at least 10 times. 2nd: Your mental fatigue is no higher than 50%. Once Mental Fatigue is past 50%, your odds of success start dropping hard. That should make the reliable production too difficult to obtain without save scumming. Sound reasonable?