Hm the usual method foobar2000.exe {allfilepath$} works OK for me and it's fast.
The only progressbar that can appear is Foobar's own progressbar when there are lots of files, but that can be disabled with the foobar's /immediate parameter as per docs:
foobar2000 always sorts incoming files using the pattern configured under "Preferences > Shell Integration". Because there is a possibility that more files belonging to the same batch will be passed to the program, adding the items really to a playlist is postponed until no new file is received for a short while, because only with the full set of incoming files they can be correctly sorted. Use this option to disable this behaviour for the currently added items.