The problem is there will always be small tasks and those tasks might actually delay longer more important tasks. At some point you need to prioritize what is most important with your time.
If you’re always grinding small tasks to make time for a larger task that too will burn you out.
The point is there are lots of small tasks you can do when you're brain isn't capable of doing focused work. Certain work requires careful thinking and can only be done when you're in top shape to be done effectively. Prioritize that work when you're energetic, etc. Do the small tasks when you're not so you're high quality time get's used well.
Those tasks don't require concentration, yes, but they drain your energy supply just as well as those that do. This means that the likelihood you'll be energetic and creative tomorrow diminishes the more of them you pile up at the end of your shift.
So IMO do 2-3 of those and call it a day. You have to be in a work shape tomorrow as well.
If you’re always grinding small tasks to make time for a larger task that too will burn you out.