Quick Glance at the most optimal prefer list:
VIP Tickets are a must
Prefer List
Abyssal Demons (Magic)
Airut (Melee)
Dark Beasts (Range)
Glacors (Magic)
Muspah (Magic)
Block List
Elves
Greater Demons
5 of any tasks with 10 weight
Un-toggle every task that is persuadable except for Glacors and Muspah
Cancel
Cancel any tasks that is not preferred
If you follow the above exactly, you'll break even on slayer points but still only do those 5 tasks indefinitely for maximized exp