I have a suggestion for fixing the lag.
Everyone hates the lag(and of course you knew that already).
So let me begin,
Some issues are only present when of course the object causing the problem is present, so even a reset can sometimes only be a temporal fix because someone may make the buggy item again.
So my suggestion is, you make a full server backup and let Arcana Tech undergo some kind of kind of "Debug Week" where you remove or disable many mods and advise the community to disable them in the main menu. That way you could isolate the issue faster because no new update would have to roll out everyday to test the server under full load.
This of course is only a suggestion and should in no way be advising and i really appreciate the efforts of the server team to fix the issues.^^