Ambergris stacking is a very dangerous thing to have as it give 300hp instant heal to magma...
In a turret soaking or boss fight situation this could be considered OP.

If server owners want to adjust the stacks of Ambergris then put this in the Game.ini

ConfigOverrideItemMaxQuantity=(ItemClassString="PrimalItemResource_Ambergris_HS_C",Quantity=(MaxItemQuantity=1, bIgnoreMultiplier=true))

This will put the stack back to 1