Oh crap! Very sorry to hear that. I was only abe to test this mod on singleplayer so far. It got enabled this morning (CET) on my own dedicated server with active players online. But until now I was at work so I couldn't test it....

Are you having higher harvest rates on your server configured?
The reason I'm asking is, because I'm having another mod called "Minor Stacks" which was causing lags on my server with 20x harvest rates, while someone was harvisting with a bronto. That's why I reduced the stack size of the vanilla berries from 1000 to 500 and increaded the weight from initially only 1/10 (0.01) to 1/2 (0.05) of the default weight.

Another guess of mine is also somehow aming on the rates. Because I added the new berry to the bushes it maybe increases the total amount of berries you gather per bush. I thought the Entry-Weight thing will somehow equal out the total amount of berries, but maybe they are put on top to the already existing berries you gather. which means more berries (maybe to much) per swipe....

A last guess, which would be really sad news. Because the mod remaps every bushes inventory on the hole map, ARK is maybe simply not able to handle this....

EDIT:
I've testet it on my Server. I don't see any lags because of this berry. And the community on this server also didn't experienced any lag. But I have to adamit I've adjusted my berry harvest rates for some "minor" berries some days ago like this:

HarvestResourceItemAmountClassMultipliers=(ClassName="PrimalItemConsumable_Berry_Amarberry_C",Multiplier=0.5)
HarvestResourceItemAmountClassMultipliers=(ClassName="PrimalItemConsumable_Berry_Azulberry_C",Multiplier=0.5)
HarvestResourceItemAmountClassMultipliers=(ClassName="PrimalItemConsumable_Berry_Mejoberry_C",Multiplier=1.0)
HarvestResourceItemAmountClassMultipliers=(ClassName="PrimalItemConsumable_Berry_Narcoberry_C",Multiplier=1.0)
HarvestResourceItemAmountClassMultipliers=(ClassName="PrimalItemConsumable_Berry_Stimberry_C",Multiplier=0.5)
HarvestResourceItemAmountClassMultipliers=(ClassName="PrimalItemConsumable_Berry_Tintoberry_C",Multiplier=0.5)

So maybe the idea of to much berries harvested at once is still possible...

Yeah, my rates are increased to 15x for harvest. And on that my stacks reach 5k

My stack size is 5,000 for berries and anytime I swipe with a Bronto I myself won't be able to do anything, harvest rate is set to 20x, I don't lag as I can still see the counters going up and move my camera while the stack size increases and my harvest collects into my Bronto, as for my server experiencing lag I haven't noticed anything.. from what I can tell it's only client side lag as you "catch up" to what the server already said you harvested lol.. However anyone is more than welcome to get on my server and test it out, just shoot me a PM and I will send you the info to connect.. I also have 70+ mods on the server, just a heads up O.o