Binnie just removed all the thousands of fence recipes in favour of a better system.
This just inspired me. Forge multipart recipes were added to the ae2 system a few weeks back. I'm going to try removing them.
Update: this didn't fix it. I haven't done a server restart yet.
Does anyone know if there's a way to suppress console spam? Generic forge errors and warnings are probably hogging quite a bit of memory bandwidth. It's incredibly annoying that the errors never include a stacktrace. I spent weeks trying to track down the source and eventually gave up.