Very interesting. Though the sample size is so far extremely limited so this is all speculation, some of us are noticing that U152 -> L2 -> Z49 -> Z142 is so far showing up a lot in Britain.
My own breakdown is
U152> L2> Z41150> Z49,Z68> Z142> FGC22963,FGC22969> FGC22968,ZP67> FGC22942,S18325...