The mod is quite nice, but there's one thing that REALLY bugs me.
Due to the prospector's range, for larger ore fields you need to place them inside the fields.
But due to the miner's range only being 5, this leaves blind spots in the mining area, even with the most dense configurations possible (Pretty sure that the best case configuration has to leave one tile unmined)

If the prospectors could mine the ore directly beneath them, this would not be an issue.

Also, is it possible to enrich the ore fields before starting to mine them?

Yes, you can enrich before you mine. It's intended that you'll need multiple prospectors to cover a field and some might need to be in the middle of the field.

I've thought about adding wider miners so they could mine under prospectors, but there's a lot of mods that do that already.

Enriched ore mining is slower, right?

Yes, it's intended to be a tradeoff.