In a clear, solid free solution; yes, DMT will float to the top (as is evident when converting fumarate or doing a second A/B cleanup). In a solution laden with bark it's much less clean cut. Some of the precipitated alkaloids may be caught amongst the solids and trapped at the bottom of the muck. You could combat this by gently agitating the mixture through vibration after an initial period of settling.
"Laws alone can not secure freedom of expression; in order that every man present his views without penalty there must be a spirit of tolerance in the entire population." -Albert Einstein
I'm not a big fan of SWIM. I mean, I've never met the guy, but any time I hear about him, he's doing something sketchy.