If cron is broken for you, than the logic solution would be to replace it with something that does work for you. But do so at the right place and abstraction. That's hardly ever the runtime or in the app.

Do One Thing (and do it well).

A special domain specific scheduler microservice? One of the many Cron replacements? One of the many "SaaS cron"? Systemd?

This problem has been solved. Corner cases ironed out. Free to use.

Same for ENV var as configurations (as opposed to inventing yet another config solution), file permissions, monitoring, networking, sandboxing, chrooting etc. the amount of broken, insecure or just inefficient DIY versions of stuff handled in an OS I've had to work around is mind boggling. Causing a trice a loss: the time taken to build it. That time not spent on the business domain, and the time to them maintain and debug it for the next fifteen years.