After applying current ffmpeg.git as of May 25: ae0f71a387f05be7ac90d545af4d3aeb8e1cca89 and applying Andrew's patches:
0001-Add-check-for-nb_inputs-before-calling-avfilter_get_.patch
0002-Same-possible-crash-fix-in-ffstreamaudio-for-dynamic.patch
0003-Do-not-filter-out-dynamic_input-filters.patch
0004-HACK-ffmpeg-8.0-build.patch
CinGG builds but none of the ffmpeg plugins work. The Video plugins crash (did not try them all, but a few like F_boxblur) when added to the timeline and then click on "Show Controls. The Audio plugins do not crash but you get the warning tone only when you play them (again, I did not try them all, but F_chorus was one of them).