This is a must if you're playing with 10 year later mod, also it should be included in vanilla PZ if you want to make this for 1 year later, etc.

Yes sure thing.

Although it doesn't seem like it'll receive further updates, would I be allowed to add this mod to a modpack, assuming I don't touch any of the code and issued proper credit both in the modpack description and in a Discord channel for contributors?

Great idea.