There are several really excellent schedulers out there - why is the core team starting from scratch?
In particular a shout out to Schedy (Heaty will die, Schedy be born!) - a fantastic, hugely flexible scheduler by @roschi. This is a mature project - I’ve been using it for 2 years.
Yes, it is (and probably has to be) YAML, but the flexibility it offers is top draw.
Please bring these projects in, rather than start from scratch with something that is often less functional.
The New BLE is a great example where a contributors hard work has been absorbed into core - well done for that.
Related -