Earlier quoted context omitted.
Employees benefit from calls out of hours. How? The employer is able to offer better service to customers, and make more money, and the employee can negotiate a higher salary from the more profitable business. Employees who are inflexible cannot offer the same level of service to their employer and its customers; they'll on-average be paid less and measures like this increase production costs, making goods and servic…
If overnight service is that critical and profitable, hire a night shift.
You genuinely think a seed stage startup should hire a complete "night shift" to ensure no engineers ever get paged "after hours?" This simply kills startups completely.