Performance test result.
(by time builtin in zsh.)

vflib-1.4 with-platfonts with-bogus-speedup-patch
GS_LIB=kanji ./gs -dNOPAUSE kanji/allkanji.ps -c quit  264.18s user 1.58s system 93% cpu 4:43.19 total

vflib-1.4 without-platfonts with-bogus-speedup-patch
GS_LIB=kanji ./gs -dNOPAUSE -dNOPLATFONTS kanji/allkanji.ps -c quit  413.45s user 1.48s system 97% cpu 7:06.61 total

vflib-1.4 with-platfonts without-bogus-speedup-patch
GS_LIB=kanji ./gs -dNOPAUSE kanji/allkanji.ps -c quit  517.10s user 2.10s system 98% cpu 8:48.83 total

vflib-1.4 without-platfonts without-bogus-speedup-patch
GS_LIB=kanji ./gs -dNOPAUSE -dNOPLATFONTS kanji/allkanji.ps -c quit  665.92s user 1.55s system 98% cpu 11:17.19 total

vflib-1.2 with-VFlibBM
GS_LIB=kanji ./gs -dNOPAUSE ../../src/gs5.10-dev/kanji/allkanji.ps -c quit  306.32s user 2.57s system 91% cpu 5:38.07 total

# bogus-speedup-patch does not affect VFlibBM performance because the
# patch is applied to koutline.ps and VFlibBM does not use koutline.ps.