Interesting topic, I will add my 2c, here is my graph:
At $20 ABI I'm around 15ish BB/100, there is some lower stakes clustered in there. At lower stakes (sub $10), I've maintained 25ish over 50k hands IIRC and I seldom dropped more than 20 BIs.
Basically, if you are above 10bb/100, it's very hard to severely downswing. I've dropped 40 BIs in that graph, but it was mostly using aggressive rebuy strategies which I've realized was adding to the issue, without them it'd probably be around 30ish, so still downswinging but that only last 2-3 weeks and now I'm back up over 100 BIs at since I started with the graph.
I will also add that there have been some very close calls which the difference between flips/JJ v AA or QQ v KK/flush over flush on final tables is possibly even 500+ BIs over the last month, some of the placings:
6/115, 11/1600, 23/124, 18/150, 18/800, 26/720, 19/140, 45/706, 17/132, 2/166, 6/283, 11/900
So although expecting to win them all is not realistic at all, with slightly better luck I could be up a lot more than just 100 BIs over that sample.