When starting the client its gets to the point where the below occurs and takes quite a long while significantly slowing down the client loading to 5min+ just in the aspect checking alone.

20:54:59] [ThaumicJEI Aspect Cache/INFO] [thaumicjei]: ItemStack Aspect checking at x%
[20:55:04] [ThaumicJEI Aspect Cache/INFO] [thaumicjei]: ItemStack Aspect checking at x%>

Impossible it happens in another Thread

This is a snippet for the client im currently loading an waiting to finish loading. https://gist.github.com/Morpheus1101/b58fc727799b182f62d16eb30714d350

It can't slow down the client thread, because it doesn't happen in the client thread. It doesn't make sense, I have tested it in the pack ATM where the aspect checking takes 17min and the client loads in 6.

With this pack, the client dosent finish loading to be functional until after the Aspect Checking has finished, which takes quite sometime, but if this is intentional then so be it.

Can I get a screenshot of the client while its waiting?

And now its making a liar out of me lol ... im just gonna call it gremlins for the last day and say they're now gone as i got no further explanation.