Simplify@Module[{k=3, q}, Series[E^((∑_(j=2)^k) (((((1-q))^j)(x^j))/(j(1-(q^j))))) /. q->(E^(γ e h)), {e,0,k}]]

Simplify@Module[{k=3, q}, Series[E^((∑_(j=2)^k) (((((1-q))^j)(((h x))^j))/(j(1-(q^j))))) /. q->(E^(γ e h)), {e,0,k}]]

t1=Collect[Last@(Subscript[Λ, QU])[{ξ,η,δ},{x,y}], ϵ, Simplify]

t2=Collect[Last@(Subscript[Λ, QU])[ℏ{ξ,η,δ},{x,y}], ϵ, Simplify]

LeafCount /@ {t1,t2}