Its hard to say with the picture. The bug is blurry, But I think your correct. Only other bug that comes to mind with that shape is a white mealybug which will be more on the leaves or stems.
Never had spring tails personally, But from what I have read they are harmless and nothing to worry about.
So after a little research I'm pretty sure they are spring tales as I only noticed after watering when they came up for a little swim.
Also using a coco base so it makes sense. Annoying because I actually needed some for my ants a few months back lol. But I am still concerned it could be a problem.
I'm just guessing at this point