Yes, enchantments that boost skills are halved when found on random items dropped from monsters. But not on items that you enchant yourselves.In the normal game, you can create level 4 and level 5 enchantments (with skill maxima of 12 and 17 respectively), while dragons and blood titans can drop level 6 items (stats up to +25 or skills halved to +12).
It looks like our enchantment maximum is higher in this mod. (I made an Arms +23 helm!) Maybe because we get to create level 6 enchantments, or maybe because the range for level 5 items has been increased. I haven't tested this to figure out which.
BV