Enemy 2.0 groupings and waves gain a biome component, which player can keep track of by background.
As a rage inducing example:
Red Sun have higher rates of Wardens, Hives, Juggernauts, Scion, Beamcasters, Shreddermines.
Blue Nebula have higher rates of Minelayers, Eclipses, Spitfire.
Neutral Void have higher rate of Snappers, Serpents, Constructors, Pulsebug, Saucers, Celestials.
[Wild mod scope]
Increasing chance to spawn out of wave enemies on recursive wild effect.
+x% chance for incorrect biome wave per recursive.
Increased chance to spawn SPECIFIC enemy type out of normal wave group.
Heavy Caliber, +1% chance for an enemy of classification [B] in wave to be replaced by say, Saucer?
Double tap, +2% chance for an enemy of classification [B] in wave to be replaced by say, 5 pulsebug? Instead of 24 saucer wave you could get 22 saucer 10 pulsebug or something weird.