Krausened out after 2 days?

Two days ago I brewed a batch of Irish Draught ale according to the Northern Brewer recipe. I pitched a 1L starter of WL Irish Ale yeast and after 24hrs the krausen was coming out of the blow-off tube. 48 hours later the krausen has completely disappeared, but there's still quite a bit of activity (i.e. yeast swiriling around). I'm not particularly concerned, I just find it very curious to see that rapid action. I wonder if the use of flaked oats had anything to do with it. I know a starter speeds things up, but WOW!

That looks perfectly normal to me!

Seems ok. RDWHAHB

Yeah, I'm cool with it, just never seen it happen that fast. I'm willing to bet I'll be able to bottle that much quicker. I just had one of my Scottish ales (7%ABV), so I'm nice and relaxed now.

Yeah, it's normal, but it's probably still fermenting. Wait for at least a week before checking final gravity.

Edit: I also suggest leaving it two weeks. Let the yeast finish the job.

2-3 for krausen to die down is normal. Its usually when I expect to swap the tube for an airlock.

I generally do a three-week primary, but since using starters I check the gravity after about two weeks, to see how things are going.