I'll tell you what I've always done Ken (BTW, I always use 3068 for Hefe). One of my exceptions for using a secondary - as soon as krausen just begins to fall, transfer to a secondary. This leaves trub behind, but lets the yeast in. The sediment in the bottom of the secondary is yeast, which we know in 3068 stays suspended for several days. Transfer most of this to your keg. When it starts pouring too clear , take the keg out and tip it upside down - counterintuitive, right? I always attenuate per Wyeast doing this. Works like a champ.