I know this is almost a month old, still, wanted to add something:
Im running helmod on a linux headless server, with more other mods, sure.
Everyone (including me) will get desynced once I open certain interfaces, like to pick a recipe.
When I connect locally and open that interface (pick recipe), the whole server hangs for 2 seconds.
Server is running fixed tick rate, so I'm trying to turn that off for now, see if it stops the desync.
My assumption is that there is maybe too much syncing going on, but can't find out whether I could find proof for that / in which logs I should look, without logging the exact upd packets themselves.
Big big maybe, if you feel like working on the mod, consider something like a pure clientside / offline-mode where stuff only gets calculated per-player without server interaction?
PS: thanks for your great work ;) Love what the mod does to more complex playthroughs.