Here's an overview of the included enchantments with their descriptions (which can show in-game, if configured to in CoFH Core):
Excavating: Harvests additional blocks in a radius.
Insight: Increases experience gain when using the item.
Reach: Increases the distance that the wielder can interact with things.
Trueshot: Increases the accuracy and speed of arrows, and allows them to pierce.
Volley: Additional arrows are fired with each shot. Only one arrow is consumed.
Furrowing: Tills additional blocks in a line.
Tilling: Tills additional blocks in a radius.
Weeding: Clears plants while tilling blocks.
堡垒: Prevents the wielder from being knocked back.
For the most part, vanilla enchantment overrides simply allow the enchantment to apply to more items - Protection enchantments can apply to Horse Armor. Many sword-only enchantments can apply to Axes as well. Two enchantments with large changes, however are Mending and Frost Walker.
If the Mending override is enabled (默认关闭), Mending is replaced with Preservation - XP orbs no longer repair the item, but the item can be repaired (and only repaired, not upgraded) at an Anvil for no additional cost. Essentially, the stacking penalty is removed, and the item can last indefinitely but requires manual repair.
If the Frost Walker override is enabled (默认开启), then Frost Walker will also work when on Horse Armor! There is an additional configuration option to allow Frost Walker to work on Lava blocks (for both Players and Horses), creating Glossed Magma: