Is there any advantage to holding on to multiples of mods instead of selling them? I have a ton of multiples of mods any reason to not sell them apart from holding onto each fusion level for lower level guns? Do I need to have multiple mods to apply them to multiple configs/guns?
If I have a config A on a mk1-bo and I use for example preassure point does the instance of the mod get used up? Can I usethe same instance of preassure point on let's say heat sword?
There is really only one major advantage to keeping a few multiples of mods. (I will begin with a note that rare mods can often times have some sort of demand, and--if worth the platinum--are probably better off sold). Like you mentioned, having some mods at various ranks can be useful. For example, maybe you can fit a max Vitality on one frame or a max Serration on a primary, but not on another. Having a few copies of staple mods are good.
However, there is no advantage to keeping large numbers of mods that you don't need/can't sell for plat. You don't need 200 copies of redirection. These are best either sold for credits (not recommended), or broken down into Endo (recommended).
