My only conundrum is the Ardennes I repitched where I used the entire amount of slurry I harvested and it simply would not drop out without fining.
Are you sure it was the yeast that didn't want to drop out? I have a problem with Maris Otter malt in that it always leaves my beer cloudy and I have to use finings. I know its not yeast that's causing the haze b/c I checked it under the microscope.
I assumed, but I can't say I'm sure. Thinking about it now, I had two batches of dubbel that I needed to fine and my quad took FOREVER to drop clear, but eventually did. Three different yeasts, all repitched (Chimay, Ardennes, and Trappist High Gravity). I'd have to check if they all had the same base malt, which is possible. It would have been Pilsner malt, though, not MO. Also, I only do a partial mash of 5lbs and the balance comes from DME.
I did have the same problem with a stout, but I cultured up the yeast from the dregs in a bottle so that definitely had selection for the least flocculent.
I've not had the problem with my English ales (using MO as a base). I'm on gen 3 or 4 of London ESB yeast right now so I'll check the two batches of porter this week and see how it looks. That yeast typically floccs like crazy and did so in the starters.