  We generalize multivariate hook product formulae for $P$-partitions. We use
Macdonald symmetric functions to prove a $(q,t)$-deformation of Gansner's hook
product formula for the generating functions of reverse (shifted) plane
partitions. (The unshifted case has also been proved by Adachi.) For a
$d$-complete poset, we present a conjectural $(q,t)$-deformation of
Peterson--Proctor's hook product formula.
