It is rather interesting how the rendering of the EndermanSkull is taking this much client thread time.
Spotted in a profile @Darkosto made while testing in his SF3 world. After removing the 2 skulls he had in his base he went from 180 fps to 300 fps.

Happend on EnderIO - 1.10.2-3.0.1.138_beta (latest on curse at this time), not sure about the forge version.

.nps file

Not really our code that's slow. It's that "models will make rendering sooo much faster"-code of vanilla.

Also, when looking at the other TESRs and scaling their total time by the number of times they are executed, they take about the same time.

That is quite the lightmap update

lex says, fry would need to take a look to see if those percentages are normal...

@HenryLoenwind Lex has been telling me to talk with Fry as well regarding the lighting updates. I think you may be able to have a more detailed conversation with him than I could. Is it possible for me to pass along any and all logs/samples to help point this issue out? I'd like to assist in, hopefully, eliminating that performance loss if possible :)