To my knowledge, there seems to be no way to really grind for masterwork cores at the moment and they are essential for infusing gear into your best weapons and armor. We desperately need a way to reliably acquire them besides exploiting the drifter. (Which has been patched recently) My solution to this situation would be to remove masterwork cores from infusion altogether. If Bungie truly believes that they need masterwork cores for infusion, they should reduce the price of cores from spider greatly or just make bounties guarantee a masterwork core each time. If that is too much, then make specific bounties that reward masterwork cores. Several bounties that reward a total of 10-15 each day might work. Another possibility could be to add masterwork cores to powerful gear drops. Personally, I believe that masterwork cores should only be used for the masterwork process of upgrading the slight bonus that weapons receive and the damage resistance that armor gives when master worked. If this isn’t possible, then please just make them easier to obtain because In this current state, it is absurdly difficult and time consuming to get them. Adding planetary materials to the infusion process made sense because they were pretty much useless and now it adds that slight bit of difficulty to make your favorite gear more powerful. But with masterwork cores, they already played an important role in improving your gear, but adding them to infusion was very excessive in my opinion.