The interesting thing about my job is that I will have lulls or avalanches in work. Most of my tasks involve liaising with external stakeholders, and on the side managing staff.

The thing about the new task is that there is no telling how much in a given year it will take of my time; it's responding to external complaints to a larger organizational process, so we could either get loads of complaints, or not at all. It's all dependent on various factors.

Which makes it ever-more hard to justify asking for compensation now given it may not involve a lot of work in the end.