Finally got around to giving it a spin and it seems to work. Thank you! A. Bart Schaefer wrote:
You could try changing (near the end of _make):
         _requested targets expl 'make targets' \
           compadd -- ${(k)TARGETS}&&  ret=0
to
         _requested targets expl 'make targets' \
           compadd -Q -- ${(k)TARGETS}&&  ret=0
Thereafter the _expand completer should be able to resolve them into
file names.
Any zsh-workers have an opinion on whether this would be correct for all
targets?  Should we just make this change in the distribution?