MH Sky Isles runs fine in the Monster Hunt format as it is at present. However true to the co-op format, once you pick up any health or armour, it is gone forever. The weapons and ammo regenerate properly for MH, but we need a mapper to fix up the health and armour so that they regenerate also.
The map is still winnable, but can be tough going near the end.
Hint: When you get the front door to the church open, do not shoot at the boss inside. Just run up to the altar and press the button behind. THEN shoot at him. He's really tough to kill. You really need a full team to take him out. I just leave him alone when I'm by myself in that map.