I have a Suggestion that would help the antimatter-chemistry in terms of Performance.
Since there're lag issues ( mostly cause of offline Chunkloaders ) i would suggest changing the FTB Utilities Chunkloaders to be online Chunkloaders, so they just load when the Player is online and actively playing.

Offline Chunkloaders are just horrible imo.
Pros:

• For the Player the Chunk loads when he's offline
  Cons:
• 24/7 Loading of the Chunk, performance impact
• Stacks with mostly every new player
• ACTIVE Players that play hours and hours are feeling the lag of offline players

Here's a reddit post where it shows the config if you consider changing it.
https://www.reddit.com/r/feedthebeast/comments/8wui2b/ftb_utilities_chunk_loading_question/

We have already taken a lot of action in the last week regarding chunkloading, especially for players who haven't been on the last ~2 weeks. We are still fiddling with performance, but this will be an option of last resort