I applies to regular market conditions, it is either in consolidation or expansion. I know what you talking about with Sessions, but i've found that yes some participants come and go, but Forex is traded 24/5 therefore even in Asia Session market sometimes expands and ranges in New york session and vise versa. Even overnight there are often trendig phases in EUR/USD or Gbp/USD. So to keep it simple, Up, down or sideways. I just need a filter to avoid when market is calm and when Momentum starts to come in.
Same thing with Volume for example. Often, first comes Momentum and then comes Volume.
For some times thought that ADX might help with that, but often even when is stays often certain level there is consolidation and vise versa.