I live in Haida Gwaii where there is lots of skunk cabbage.
I am finding mixed information on composting these plants. It would seem that if you did not intend to consume the plant using this compost, then it can be done if composted properly, since it is poisonous.
If you do intend to use this compost on edible plants, then I would not recommend composting it at all. Burn, or dispose of the plants in a manner in which it will not leech into waterways, or water supply.
This article will give you more information on the plant: https://www.gardeningknowhow.com/ornamental/flowers/skunk-cabbage/skunk-cabbage-facts.htm
This article will help you to compost properly: https://www.gardeningknowhow.com/ornamental/flowers/skunk-cabbage/skunk-cabbage-facts.htm
This collection of articles will give you information on ingredients for good compost: https://www.gardeningknowhow.com/category/composting/ingredients
It isn't usually recommended to fertilize them, rather, they should be potted up to the next size container, or the soil brushed off of the roots and repotted into fresh soil in the same container.
If you do choose to feed it a synthetic fertilizer, then doing so at 1/4 strength would be the best start until you know how it reacts. Otherwise, topping with compost would be another solution.
https://www.gardeningknowhow.com/ornamental/flowers/skunk-cabbage/skunk-cabbage-facts.htm
I would also opt to test the soil before feeding.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm